Patent Publication Number: US-2023159374-A1

Title: Colored glass articles having improved mechanical durability

Description:
This application is a continuation of U.S. application Ser. No. 17/843,096, filed on Jun. 17, 2022, which claims the benefit of U.S. Provisional Application Ser. No. 63/318,553 filed on Mar. 10, 2022, U.S. Provisional Application Ser. No. 63/212,179 filed on Jun. 18, 2021, U.S. Provisional Application Ser. No. 63/347,095 filed on May 31, 2022, U.S. Provisional Application Ser. No. 63/347,201 filed on May 31, 2022, the content of each of which are relied upon and incorporated herein by reference in their entirety. 
    
    
     FIELD 
     The present specification generally relates to glass compositions and glass articles and, in particular, to glass compositions and ion-exchangeable, colored glass articles formed therefrom. 
     TECHNICAL BACKGROUND 
     Aluminosilicate glass articles may exhibit superior ion-exchangeability and drop performance. Various industries, including the consumer electronics industry, desire colored materials with the same or similar strength and fracture toughness properties. However, simply including colorants in conventional aluminosilicate glass compositions may not produce the desired color and/or result in colored glass articles suitable for use in electronic devices transmitting and/or receiving high frequencies (e.g., frequencies of fifth generation (5G) wireless). 
     Accordingly, a need exists for an alternative colored glass articles that minimize disruption of transmitting and/or receiving of high frequency while providing the high strength and fracture toughness necessary for use in electronic devices. 
     SUMMARY 
     According to a first aspect A1, a glass composition includes greater than or equal to 50 mol % and less than or equal to 70 mol % SiO 2 ; greater than or equal to 10 mol % and less than or equal to 20 mol % Al 2 O 3 ; greater than or equal to 1 mol % and less than or equal to 10 mol % B 2 O 3 ; greater than or equal to 7 mol % and less than or equal to 14 mol % Li 2 O; greater than 0 mol % and less than or equal to 8 mol % Na 2 O; greater than 0 mol % and less than or equal to 1 mol % K 2 O; greater than or equal to 0 mol % and less than or equal to 7 mol % CaO; greater than or equal to 0 mol % and less than or equal to 8 mol % MgO; and greater than or equal to 0 mol % and less than or equal to 8 mol % ZnO. R 2 O+R′O is less than or equal to 25 mol %, wherein R 2 O is the sum of Li 2 O, Na 2 O, and K 2 O and R′O is the sum of CaO, MgO, and ZnO. The glass composition includes at least one of NiO+Co 3 O 4 +Cr 2 O 3 +CuO is greater than or equal to 0.001 mol %, CeO 2  is greater than or equal to 0.1 mol %, and TiO 2  is greater than or equal to 0.1 mol %. 
     A second aspect A2 includes the glass composition according to the first aspect A1, wherein NiO+Co 3 O 4 +Cr 2 O 3 +CuO is greater than or equal to 0.001 mol % and less than or equal to 3 mol %. 
     A third aspect A3 includes the glass composition according to the first aspect A1, wherein CeO 2  is greater than or equal to 0.1 mol % and less than or equal to 2 mol %. 
     A fourth aspect A4 includes the glass composition according to the first aspect A1, wherein TiO 2  is greater than or equal to 0.1 mol % and less than or equal to 2 mol %. 
     A fifth aspect A5 includes the glass composition according to the first aspect A1, wherein NiO+Co 3 O 4 +Cr 2 O 3 +CuO+CeO 2 +TiO 2  is greater than or equal to 0.001 mol % and less than or equal to 10 mol %. 
     A sixth aspect A6 includes the glass composition according to any one of the first aspect A1 to the fifth aspect A5, wherein R 2 O+R′O is greater than or equal to 7 mol % and less than or equal to 25 mol %. 
     A seventh aspect A7 includes the glass composition according to any one of the first aspect A1 to the sixth aspect A6, wherein R 2 O is greater than or equal to 7 mol % and less than or equal to 25 mol %. 
     An eighth aspect A8 includes the glass composition according to any one of the first aspect A1 to the seventh aspect A7, wherein R′O is greater than or equal to 0 mol % and less than or equal to 12 mol %. 
     A ninth aspect A9 includes the glass composition according to any one of the first aspect A1 to the eighth aspect A8, wherein 3.802946+0.01747*B 2 O 3 +0.058769*Al 2 O 3 +0.080876*Li 2 O+0.148433*Na 2 O+0.153264*K 2 O+0.045179*MgO+0.080113*CaO is less than or equal to 6.8. 
     A tenth aspect A10 includes the glass composition according to any one of the first aspect A1 to the ninth aspect A9, wherein R 2 O−Al 2 O 3  is greater than or equal to −8 mol % and less than or equal to 4 mol %. 
     An eleventh aspect A11 includes the glass composition according to any one of the first aspect A1 to the tenth aspect A10, wherein the glass composition comprises greater than or equal to 7.5 mol % and less than or equal to 13.5 mol % Li 2 O. 
     A twelfth aspect A12 includes the glass composition according to any one of the first aspect A1 to the eleventh aspect A11, wherein the glass composition comprises greater than or equal to 0.1 mol % and less than or equal to 7 mol % Na 2 O. 
     A thirteenth aspect A13 includes the glass composition according to any one of the first aspect A1 to the twelfth aspect A12, wherein the glass composition comprises greater than or equal to 0.1 mol % and less than or equal to 0.7 mol % K 2 O. 
     A fourteenth aspect A14 includes the glass composition according to any one of the first aspect A1 to the thirteenth aspect A13, wherein the glass composition comprises greater than or equal to 0.25 mol % and less than or equal to 6.5 mol % CaO. 
     A fifteenth aspect A15 includes the glass composition according to any one of the first aspect A1 to the fourteenth aspect A14, wherein the glass composition comprises greater than or equal to 0.25 mol % and less than or equal to 7 mol % MgO. 
     A sixteenth aspect A16 includes the glass composition according to any one of the first aspect A1 to the fifteenth aspect A15, wherein the glass composition comprises greater than or equal to 0.5 mol % and less than or equal to 7 mol % ZnO. 
     A seventeenth aspect A17 includes the glass composition according to any one of the first aspect A1 to the sixteenth aspect A16, wherein the glass composition comprises greater than or equal to 0.01 mol % and less than or equal to 1 mol % Fe 2 O 3 . 
     An eighteenth aspect A18 includes the glass composition according to any one of the first aspect A1 to the sixteenth aspect A16, wherein the glass composition comprises greater than or equal to 0.001 mol % and less than or equal to 0.5 mol % Fe 2 O 3 . 
     A nineteenth aspect A19 includes the glass composition according to any one of the first aspect A1 to the eighteenth aspect A18, wherein the glass composition comprises greater than or equal to greater than or equal to 0.01 mol % and less than or equal to 1 mol % SnO 2 . 
     A twentieth aspect A20 includes the glass composition according to any one of the first aspect A1 to the nineteenth aspect A19, wherein the glass composition comprises greater than or equal to 12 mol % and less than or equal to 17.5 mol % Al 2 O 3 . 
     A twenty-first aspect A21 includes the glass composition according to any one of the first aspect A1 to the twentieth aspect A20, wherein the glass composition comprises greater than or equal to 2 mol % and less than or equal to 9 mol % B 2 O 3 . 
     A twenty-second aspect A22 includes the glass composition according to any one of the first aspect A1 to the twenty-first aspect A21, wherein the glass composition comprises greater than or equal to 12 mol % and less than or equal to 18 mol % Al 2 O 3 . 
     A twenty-third aspect A23 includes the glass composition according to any one of the first aspect A1 to the twenty-second aspect A22, wherein the glass composition comprises greater than or equal to 50 mol % and less than or equal to 67 mol % SiO 2 . 
     According to a twenty-fourth aspect A24, a colored glass article includes greater than or equal to 50 mol % and less than or equal to 70 mol % SiO 2 ; greater than or equal to 10 mol % and less than or equal to 20 mol % Al 2 O 3 ; greater than or equal to 1 mol % and less than or equal to 10 mol % B 2 O 3 ; greater than or equal to 7 mol % and less than or equal to 14 mol % Li 2 O; greater than 0 mol % and less than or equal to 8 mol % Na 2 O; greater than 0 mol % and less than or equal to 1 mol % K 2 O; greater than or equal to 0 mol % and less than or equal to 7 mol % CaO; greater than or equal to 0 mol % and less than or equal to 8 mol % MgO; and greater than or equal to 0 mol % and less than or equal to 8 mol % ZnO, wherein: R 2 O+R′O is less than or equal to 25 mol %, wherein R 2 O is the sum of Li 2 O, Na 2 O, and K 2 O and R′O is the sum of CaO, MgO, and ZnO; and at least one of: NiO+Co 3 O 4 +Cr 2 O 3 +CuO is greater than or equal to 0.001 mol %; CeO 2  is greater than or equal to 0.1 mol %; and TiO 2  is greater than or equal to 0.1 mol %. 
     A twenty-fifth aspect A25 includes the colored glass article according to the twenty-fourth aspect A24, wherein NiO+Co 3 O 4 +Cr 2 O 3 +CuO is greater than or equal to 0.001 mol % and less than or equal to 3 mol %. 
     A twenty-sixth aspect A26 includes the colored glass article according to the twenty-fourth aspect A24, wherein CeO 2  is greater than or equal to 0.1 mol % and less than or equal to 2 mol %. 
     A twenty-seventh aspect A27 includes the colored glass article according to the twenty-fourth aspect A24, wherein TiO 2  is greater than or equal to 0.1 mol % and less than or equal to 2 mol %. 
     A twenty-eighth aspect A28 includes the colored glass article according to the twenty-fourth aspect A24, wherein NiO+Co 3 O 4 +Cr 2 O 3 +CuO+CeO 2 +TiO 2  is greater than or equal to 0.001 mol % and less than or equal to 10 mol %. 
     A twenty-ninth aspect A29 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the twenty-eighth aspect A28, wherein R 2 O+R′O is greater than or equal to 7 mol % and less than or equal to 25 mol %. 
     A thirtieth aspect A30 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the twenty-ninth aspect A29, wherein R 2 O is greater than or equal to 7 mol % and less than or equal to 25 mol %. 
     A thirty-first aspect A31 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirtieth aspect A30, wherein R′O is greater than or equal to 0 mol % and less than or equal to 12 mol %. 
     A thirty-second aspect A32 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-first aspect A31, wherein 3.802946+0.01747*B 2 O 3 +0.058769*Al 2 O 3 +0.080876*Li 2 O+0.148433*Na 2 O+0.153264*K 2 O+0.045179*MgO+0.080113*CaO is less than or equal to 6.8. 
     A thirty-third aspect A33 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-second aspect A32, wherein R 2 O−Al 2 O 3  is greater than or equal to −8 mol % and less than or equal to 4 mol %. 
     A thirty-fourth aspect A34 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-third aspect A33, wherein the colored glass article comprises greater than or equal to 7.5 mol % and less than or equal to 13.5 mol % Li 2 O. 
     A thirty-firth aspect A35 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-fourth aspect A34, wherein the colored glass article comprises greater than or equal to 0.1 mol % and less than or equal to 7 mol % Na 2 O. 
     A thirty-sixth aspect A36 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-fifth aspect A35, wherein the colored glass article comprises greater than or equal to 0.1 mol % and less than or equal to 0.7 mol % K 2 O. 
     A thirty-seventh aspect A37 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-sixth aspect A36, wherein the colored glass article comprises greater than or equal to 0.25 mol % and less than or equal to 6.5 mol % CaO. 
     A thirty-eighth aspect A38 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-seventh aspect A37, wherein the colored glass article comprises greater than or equal to 0.25 mol % and less than or equal to 7 mol % MgO. 
     A thirty-ninth aspect A39 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-eighth aspect A38, wherein the colored glass article comprises greater than or equal to 0.5 mol % and less than or equal to 7 mol % ZnO. 
     A fortieth aspect A40 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-ninth aspect A39, wherein the colored glass article comprises greater than or equal to 0.01 mol % and less than or equal to 1 mol % Fe 2 O 3 . 
     A forty-first aspect A41 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the thirty-ninth aspect A39, wherein the glass composition comprises greater than or equal to 0.001 mol % and less than or equal to 0.5 mol % Fe 2 O 3 . 
     A forty-second aspect A42 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the forty-first aspect A41, wherein the colored glass article comprises greater than or equal to greater than or equal to 0.01 mol % and less than or equal to 1 mol % SnO 2 . 
     A forty-third aspect A43 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the forty-second aspect A42, wherein the colored glass article comprises greater than or equal to 12 mol % and less than or equal to 17.5 mol % Al 2 O 3 . 
     A forty-fourth aspect A44 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the forty-third aspect A43, wherein the colored glass article comprises greater than or equal to 2 mol % and less than or equal to 9 mol % B 2 O 3 . 
     A forty-fifth aspect A45 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the forty-fourth aspect A44, wherein the colored glass article comprises greater than or equal to 12 mol % and less than or equal to 18 mol % Al 2 O 3 . 
     A forty-sixth aspect A46 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the forty-fifth aspect A45, wherein the colored glass article comprises greater than or equal to 50 mol % and less than or equal to 67 mol % SiO 2 . 
     A forty-seventh aspect A47 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the forty-sixty aspect A46, wherein the colored glass article has a transmittance color coordinate in the CIELAB color space, as measured at an article thickness of 1.33 mm under F2 illumination and a 10° standard observer angle, of L* greater than or equal to 65 and less than or equal to 98, a* greater than or equal to −20 and less than or equal to 10, and b* greater than or equal to −15 and less than or equal to 15. 
     A forty-eighth aspect A48 includes the colored glass article according to any one of the twenty-fourth aspect A24 to forty-seventh aspect A47, wherein the colored glass article has a dielectric constant Dk at 10 GHz less than or equal to 6.8. 
     A forty-ninth aspect A49 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the forty-eighth aspect A48, wherein the colored glass article has a thickness greater than or equal to 250 μm and less than or equal to 6 mm. 
     A fiftieth aspect A50 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the forty-ninth aspect A49, wherein the colored glass article has have a K IC  fracture toughness as measured by a chevron notch short bar method greater than or equal to 0.7 MPa·m 1/2 . 
     A fifty-first aspect A51 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the fiftieth aspect A50, wherein the colored glass article is an ion-exchanged colored glass article. 
     A fifty-second aspect A52 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the fifty-first A51, wherein the ion-exchanged colored glass article has a depth of compression 3 μm or greater. 
     A fifty-third aspect A53 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the fifty-second aspect A52, wherein the ion-exchanged colored glass article has a thickness “t” and a depth of compression greater than or equal to 0.15t. 
     A fifty-fourth aspect A54 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the fifty-third aspect A53, wherein the ion-exchanged colored glass article has a surface compressive stress greater than or equal to 300 MPa. 
     A fifty-fifth aspect A55 includes the colored glass article according to any one of the twenty-fourth aspect A24 to the fifty-fourth aspect A54, wherein the ion-exchanged colored glass article has a maximum central tension greater than or equal to 40 MPa. 
     According to a fifty-sixth aspect A56, consumer electronic devices includes a housing having a front surface, a back surface, and side surfaces; and electrical components provided at least partially within the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent the front surface of the housing; wherein the housing comprises the colored glass article according to any one of the twenty-fourth aspect A24 to the fifty-fifth aspect A55. 
     According to a fifty-seventh aspect A57, a method of forming a colored glass article includes heat treating a glass composition to form the colored glass article, the glass composition comprising: greater than or equal to 50 mol % and less than or equal to 70 mol % SiO 2 ; greater than or equal to 10 mol % and less than or equal to 20 mol % Al 2 O 3 ; greater than or equal to 1 mol % and less than or equal to 10 mol % B 2 O 3 ; greater than or equal to 7 mol % and less than or equal to 14 mol % Li 2 O; greater than 0 mol % and less than or equal to 8 mol % Na 2 O; greater than 0 mol % and less than or equal to 1 mol % K 2 O; greater than or equal to 0 mol % and less than or equal to 7 mol % CaO; greater than or equal to 0 mol % and less than or equal to 8 mol % MgO; and greater than or equal to 0 mol % and less than or equal to 8 mol % ZnO, wherein: R 2 O+R′O is less than or equal to 25 mol %, wherein R 2 O is the sum of Li 2 O, Na 2 O, and K 2 O and R′O is the sum of CaO, MgO, and ZnO; and at least one of: NiO+Co 3 O 4 +Cr 2 O 3 +CuO is greater than or equal to 0.001 mol %; CeO 2  is greater than or equal to 0.1 mol %; and TiO 2  is greater than or equal to 0.1 mol %. 
     A fifty-eighth aspect A58 includes the method according to the fifty-seventh aspect A57, the heat treating step may comprise: (i) heating the glass composition at a rate of 1-100° C./min to glass homogenization temperature; (ii) maintaining the glass composition at the glass homogenization temperature for a time greater than or equal to 0.25 hour and less than or equal to 40 hours to produce the colored glass article; and (iii) cooling the formed colored glass article to room temperature. 
     A fifty-ninth aspect A59 includes the method according to the fifty-seventh aspect A57 or fifty-eighth aspect A58, further comprising strengthening the colored glass article in an ion exchange bath at a temperature greater than or equal to 350° C. to less than or equal to 500° C. for a time period greater than or equal to 2 hours to less than or equal to 12 hours to form an ion exchanged glass article. 
     A sixtieth aspect A60 includes the method according to the fifty-ninth aspect A59, wherein the ion exchange bath comprises KNO 3 . 
     A sixty-first aspect A61 includes the method according to the sixtieth aspect A60, wherein the ion exchange bath comprises NaNO 3 . 
     Additional features and advantages of the colored glass articles described herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic representation of an example utilized in the double cantilever beam (DCB) procedure to determine the fracture toughness K IC  and a cross-section thereof; 
         FIG.  2    is a schematic representation of an example utilized in a drop test to determine drop performance; 
         FIG.  3    is a plan view of an electronic device incorporating any of the colored glass articles according to one or more embodiments described herein; 
         FIG.  4    is a perspective view of the electronic device of  FIG.  3   ; 
         FIG.  5    shows resulting microductile cracking of Knoop Scratch Threshold testing for a select inventive example; 
         FIG.  6    shows resulting lateral cracking of Knoop Scratch Threshold testing for a select inventive example; 
         FIG.  7    shows resulting microductile cracking of Knoop Scratch Threshold testing for a select inventive example; 
         FIG.  8    shows resulting lateral cracking of Knoop Scratch Threshold testing for a select inventive example; 
         FIG.  9    graphically depicts the results of an incremental face drop on sandpaper (i.e., a “drop test”) for select inventive examples and a comparative example; and 
         FIG.  10    graphically depicts the results of four-point break testing after damage with sandpaper (i.e., a “slapper test”) for a select inventive example and a comparative example. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments of glass compositions and colored glass articles formed therefrom having a desired color and suitable for use in high frequency applications. According to embodiments, a glass composition includes greater than or equal to 50 mol % and less than or equal to 70 mol % SiO 2 ; greater than or equal to 10 mol % and less than or equal to 20 mol % Al 2 O 3 ; greater than or equal to 1 mol % and less than or equal to 10 mol % B 2 O 3 ; greater than or equal to 7 mol % and less than or equal to 14 mol % Li 2 O; greater than 0 mol % and less than or equal to 8 mol % Na 2 O; greater than 0 mol % and less than or equal to 1 mol % K 2 O; greater than or equal to 0 mol % and less than or equal to 7 mol % CaO; greater than or equal to 0 mol % and less than or equal to 8 mol % MgO; and greater than or equal to 0 mol % and less than or equal to 8 mol % ZnO. R 2 O+R′O is less than or equal to 25 mol %, wherein R 2 O is the sum of Li 2 O, Na 2 O, and K 2 O and R′O is the sum of CaO, MgO, and ZnO. The glass composition includes at least one of NiO+Co 3 O 4 +Cr 2 O 3 +CuO is greater than or equal to 0.001 mol %, CeO 2  is greater than or equal to 0.1 mol %, and TiO 2  is greater than or equal to 0.1 mol %. Various embodiments of colored glass articles and methods of making the same will be described herein with specific reference to the appended drawings. 
     Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. 
     Directional terms as used herein—for example up, down, right, left, front, back, top, bottom—are made only with reference to the figures as drawn and are not intended to imply absolute orientation. 
     Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification. 
     As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise. 
     In the embodiments of the glass compositions and the resultant colored glass articles described herein, the concentrations of constituent components in oxide form (e.g., SiO 2 , Al 2 O 3 , and the like) are specified in mole percent (mol %) on an oxide basis, unless otherwise specified. 
     The term “substantially free,” when used to describe the concentration and/or absence of a particular constituent component in a glass composition and the resultant colored glass article, means that the constituent component is not intentionally added to the glass composition and the resultant colored glass article. However, the glass composition and the resultant colored glass article may contain traces of the constituent component as a contaminant or tramp in amounts of less than 0.01 mol %, unless specified otherwise herein. It is noted that the definition of “substantially free” is exclusive of NiO, Co 3 O 4 , Cr 2 O3, and CuO, which may be intentionally added to the glass composition in relatively small amounts such as, for example and without limitation, amounts less than 0.01 mol % to achieve a descried color in the resultant colored glass article. 
     The terms “0 mol %” and “free,” when used to describe the concentration and/or absence of a particular constituent component in a glass composition, means that the constituent component is not present in the glass composition. 
     The term “fracture toughness,” as used herein, refers to the K IC  value, and is measured by the chevron notched short bar method and prior to any ion-exchange processing, unless otherwise indicated. The chevron notched short bar (CNSB) method is disclosed in Reddy, K. P. R. et al, “Fracture Toughness Measurement of Glass and Ceramic Materials Using Chevron-Notched Specimens,” J. Am. Ceram. Soc., 71 [6], C-310-C-313 (1988) except that Y* m  is calculated using equation 5 of Bubsey, R. T. et al., “Closed-Form Expressions for Crack-Mouth Displacement and Stress Intensity Factors for Chevron-Notched Short Bar and Short Rod Specimens Based on Experimental Compliance Measurements,” NASA Technical Memorandum 83796, pp. 1-30 (October 1992). 
     Alternative K IC  fracture toughness measurements were performed on some samples with the double cantilever beam (DCB) procedure. The DCB specimen geometry is shown in  FIG.  1    with parameters being the crack length a, applied load P, cross-sectional dimensions w and 2h, and the thickness of the crack-guiding groove b. The samples were cut into rectangles of width 2h=1.25 cm and a thickness ranging from, w=0.3 mm to 1 mm, with the overall length of the sample, which is not a critical dimension, varying from 5 cm to 10 cm. A hole was drilled on both ends with a diamond drill to provide a means of attaching the sample to a sample holder and to the load. A crack “guiding groove” was cut down the length of the sample on both flat faces using a wafer dicing saw with a diamond blade, leaving a “web” of material, approximately half the total plate thickness (dimension b in  FIG.  1   ), with a height of 180 μm corresponding to the blade thickness. The high precision dimensional tolerances of the dicing saw allow for minimal sample-to-sample variation. The dicing saw was also used to cut an initial crack where a=15 mm. As a consequence of this final operation a very thin wedge of material was created near the crack tip (due to the blade curvature) allowing for easier crack initiation in the sample. The samples were mounted in a metal sample holder with a steel wire in the bottom hole of the sample. The samples were also supported on the opposite end to keep the samples level under low loading conditions. A spring in series with a load cell (FUTEK, LSB200) was hooked to the upper hole which was then extended, to gradually apply load, using rope and a high precision slide. The crack was monitored using a microscope having a 5 μm resolution attached to a digital camera and a computer. The applied stress intensity, K P , was calculated using the following equation: 
     
       
         
           
             
               K 
               P 
             
             = 
             
               
                 [ 
                 
                   
                     P 
                     · 
                     a 
                   
                   
                     
                       
                         ( 
                         
                           w 
                           · 
                           b 
                         
                         ) 
                       
                       0.5 
                     
                     ⁢ 
                     
                       h 
                       0.5 
                     
                   
                 
                 ] 
               
               [ 
               
                 3.47 
                 + 
                 
                   2.32 
                   
                     h 
                     a 
                   
                 
               
               ] 
             
           
         
       
     
     For each sample, a crack was first initiated at the tip of the web, and then the starter crack was carefully sub-critically grown until the ratio of dimensions a/h was greater than 1.5 to accurately calculate stress intensity. At this point the crack length, a, was measured and recorded using a traveling microscope with 5 μm resolution. A drop of toluene was then placed into the crack groove and wicked along the length of the groove by capillary forces, pinning the crack from moving until the fracture toughness is reached. The load was then increased until sample fracture occurred, and the critical stress intensity K IC  calculated from the failure load and sample dimensions, with K P  being equivalent to K IC  due to the measurement method. 
     A typical drop test is schematically shown in  FIG.  2   . Each sample  1310  was affixed to a standard test vehicle  1320 , which approximates the size, mass, and balance of a generic “smart” phone, and dropped from a drop height h onto a sheet of sandpaper  1330  having an abrasive surface  1335 . The drop height h ranged from about 0.2 meter to 2.2 meters in incremental heights of 0.1 meter. Drop testing was carried out using a 180-grit silicon carbide sandpaper surface and an 80 grit silicon carbide sandpaper surface. The drop performance is reported in terms of the maximum drop height in cm before failure of the colored glass article. 
     Surface compressive stress is measured with a surface stress meter (FSM) such as commercially available instruments such as the FSM-6000, manufactured by Orihara Industrial Co., Ltd. (Japan). Surface stress measurements rely upon the measurement of the stress optical coefficient (SOC), which is related to the birefringence of the glass article. SOC, in turn, is measured according to Procedure C (Glass Disc Method) described in ASTM standard C770-16, entitled “Standard Test Method for Measurement of Glass Stress-Optical Coefficient,” the contents of which are incorporated herein by reference in their entirety. Depth of compression (DOC) is also measured with the FSM. The maximum central tension (CT) values are measured using a scattered light polariscope (SCALP) technique known in the art. 
     The term “depth of compression” (DOC), as used herein, refers to the position in the article where compressive stress transitions to tensile stress. 
     The term “CIELAB color space,” as used herein, refers to a color space defined by the International Commission on Illumination (CIE) in 1976. It expresses color as three values: L* for the lightness from black (0) to white (100), a* from green (−) to red (+), and B* from blue (−) to yellow (+). 
     The term “color gamut,” as used herein, refers to the pallet of colors that may be achieved by the colored glass articles within the CIELAB color space. 
     The dielectric constant of the colored glass articles may be measured using a split post dielectric resonator (SPDR), as is known in the art, at a frequency of 10 GHz. The dielectric constant was measured on samples of the colored glass article having a length of 3 inches (76.2 mm), a width of 3 inches (76.2 mm), and a thickness of less than 0.9 mm. 
     The dielectric constant of the colored glass articles may also be measured over a range of frequencies from 10 GHz to 60 GHz using a double concave reflecting mirror Fabry-Perot open resonator, as is known in the art. The dielectric constant can be measured at different frequencies by adjusting the mirror spacing in the open resonator. The dielectric constant may be measured on samples of the colored glass article having a length of 120 mm, a width of 120 mm, and a thickness of 2 mm or less. While not wishing to be bound by theory, it is believed that the dielectric constant of the colored glass articles measured at 10 GHz approximates the dielectric constant at each frequency in the range from 10 GHz to 60 GHz. 
     The dielectric constant Dk of the colored glass article may be calculated according to the equation: 
         Dk= 3.802946+0.01747*B 2 O 3  (mol %)+0.058769*Al 2 O 3  (mol %)+0.080876*Li 2 O (mol %)+0.148433*Na 2 O (mol %)+0.153264*K 2 O (mol %)+0.045179*MgO (mol %)+0.080113*CaO (mol %). 
     Colorants have been added to conventional aluminosilicate glass compositions to achieve a colored glass article having a desired color and improved mechanical properties. For example, transition metal oxides and/or rare earth oxides may be added. However, simply including colorants in aluminosilicate glass compositions may not produce the desired color and/or result in colored glass articles suitable for use in electronic devices transmitting and/or receiving high frequencies (e.g., frequencies of fifth generation (5G)). 
     Disclosed herein are glass compositions and colored glass articles formed therefrom that mitigate the aforementioned problems such that transition metal oxides and/or rare earth oxides may be added to produce colored articles having the desired color and a reduced dielectric constant for use in high frequency applications while retaining the superior ion-exchangeability and drop performance of the colored glass articles. Specifically, the glass compositions disclosed herein include transition metal oxides and/or rare earth oxides to achieve a desired color. Moreover, the glass compositions disclosed herein include a relatively low concentration (e.g., less than or equal to 25 mol %) of alkali oxides (e.g., Li 2 O, Na 2 O, and K 2 O) and alkaline earth oxides (i.e., CaO, MgO, and ZnO) to achieve a reduced dielectric constant (e.g., less than or equal to 6.90). 
     The glass compositions and colored glass articles described herein may be described as aluminoborosilicate glass compositions and colored glass articles and comprise SiO 2 , Al 2 O 3 , and B 2 O 3 . In addition to SiO 2 , Al 2 O 3 , and B 2 O 3 , the glass compositions and colored glass articles described herein include transition metal oxides (e.g., NiO, Co 3 O 4 , Cr 2 O 3 , CuO, TiO 2 ) and/or rare earth oxides (CeO 2 ) to produce colored glass articles having the desired color. Moreover, the glass compositions and colored glass articles disclosed herein include a relatively low sum (e.g., less than or equal to 25 mol %) of R 2 O (i.e., Li 2 O, Na 2 O, and K 2 O) and R′O (i.e., CaO, MgO, and ZnO) to achieve a reduced dielectric constant (e.g., less than or equal to 6.8). The glass compositions and colored glass articles described herein also include alkali oxides, such as Li 2 O, Na 2 O, and K 2 O, to enable the ion-exchangeability of the colored glass articles. 
     SiO 2  is the primary glass former in the glass compositions described herein and may function to stabilize the network structure of the colored glass articles. The concentration of SiO 2  in the glass compositions and resultant colored glass articles should be sufficiently high (e.g., greater than or equal to 50 mol %) to enhance the chemical durability of the glass composition and, in particular, the resistance of the glass composition to degradation upon exposure to acidic solutions, basic solutions, and in water. The amount of SiO 2  may be limited (e.g., to less than or equal to 70 mol %) to control the melting point of the glass composition, as the melting point of pure SiO 2  or high SiO 2  glasses is undesirably high. Thus, limiting the concentration of SiO 2  may aid in improving the meltability and the formability of the resultant colored glass article. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 50 mol % and less than or equal to 70 mol % SiO 2 . In embodiments, the concentration of SiO 2  in the glass composition and the resultant colored glass article may be greater than or equal to 50 mol %, greater than or equal to 53 mol %, greater than or equal to 55 mol %, or even greater than or equal to 57 mol %. In embodiments, the concentration of SiO 2  in the glass composition and the colored resultant glass article may be greater than or equal to 50 mol % and less than or equal to 70 mol %, greater than or equal to 50 mol % and less than or equal to 67 mol %, greater than or equal to 50 mol % and less than or equal to 65 mol % greater than or equal to 50 mol % and less than or equal to 63 mol %, greater than or equal to 53 mol % and less than or equal to 70 mol %, greater than or equal to 53 mol % and less than or equal to 67 mol %, greater than or equal to 53 mol % and less than or equal to 65 mol % greater than or equal to 53 mol % and less than or equal to 63 mol %, greater than or equal to 55 mol % and less than or equal to 70 mol %, greater than or equal to 55 mol % and less than or equal to 67 mol %, greater than or equal to 55 mol % and less than or equal to 65 mol % greater than or equal to 55 mol % and less than or equal to 63 mol %, greater than or equal to 57 mol % and less than or equal to 70 mol %, greater than or equal to 57 mol % and less than or equal to 67 mol %, greater than or equal to 57 mol % and less than or equal to 65 mol % greater than or equal to 57 mol % and less than or equal to 63 mol %, or any and all sub-ranges formed from any of these endpoints. 
     Like SiO 2 , Al 2 O 3  may also stabilize the glass network and additionally provides improved mechanical properties and chemical durability to the glass composition and the resultant colored glass article. The amount of Al 2 O 3  may also be tailored to control the viscosity of the glass composition. Al 2 O 3  may be included such that the resultant glass composition has the desired fracture toughness (e.g., greater than or equal to 0.7 MPa·m 1/2 ). However, if the amount of Al 2 O 3  is too high (e.g., greater than 20 mol %), the viscosity of the melt may increase, thereby diminishing the formability of the colored glass article. In embodiments, if the amount of Al 2 O 3  is too high, the solubility of one or more colorants in the glass melt may decrease, resulting in the formation of undesirable crystal phases in the glass. For example and without limitation, when the colorant includes Cr 2 O 3 , the solubility of Cr 2 O 3  in the glass melt may decrease with increasing Al 2 O 3  concentrations (e.g., concentrations greater than or equal to 17.5 mol %), leading to the precipitation of undesirable crystal phases. Without wishing to be bound by theory, it is hypothesized that similar behavior may occur with colorants other than Cr 2 O 3 . 
     Accordingly, in embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 10 mol % and less than or equal to 20 mol % Al 2 O 3 . In embodiments, the concentration of Al 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to 10 mol %, greater than or equal to 12 mol %, greater than or equal to 12.5 mol %, greater than or equal to 13 mol %, greater than or equal to 13.5 mol %, or even greater than or equal to 14 mol %. In embodiments, the concentration of Al 2 O 3  in the glass composition and the resultant colored glass article may be less than or equal to 20 mol %, less than or equal to 18 mol %, less than or equal to 17.5 mol %, or even less than or equal to 17 mol %. In embodiments, the concentration of Al 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to 10 mol % and less than or equal to 20 mol %, greater than or equal to 10 mol % and less than or equal to 18 mol % greater than or equal to 10 mol % and less than or equal to 17.5 mol %, greater than or equal to 10 mol % and less than or equal to 17 mol %, greater than or equal to 12 mol % and less than or equal to 20 mol %, greater than or equal to 12 mol % and less than or equal to 18 mol % greater than or equal to 12 mol % and less than or equal to 17.5 mol %, greater than or equal to 12 mol % and less than or equal to 17 mol %, greater than or equal to 12.5 mol % and less than or equal to 20 mol %, greater than or equal to 12.5 mol % and less than or equal to 18 mol % greater than or equal to 12.5 mol % and less than or equal to 17.5 mol %, greater than or equal to 12.5 mol % and less than or equal to 17 mol %, greater than or equal to 13 mol % and less than or equal to 20 mol %, greater than or equal to 13 mol % and less than or equal to 18 mol % greater than or equal to 13 mol % and less than or equal to 17.5 mol %, greater than or equal to 13 mol % and less than or equal to 17 mol %, greater than or equal to 13.5 mol % and less than or equal to 20 mol %, greater than or equal to 13.5 mol % and less than or equal to 18 mol % greater than or equal to 13.5 mol % and less than or equal to 17.5 mol %, greater than or equal to 13.5 mol % and less than or equal to 17 mol %, greater than or equal to 14 mol % and less than or equal to 20 mol %, greater than or equal to 14 mol % and less than or equal to 18 mol % greater than or equal to 14 mol % and less than or equal to 17.5 mol %, or even greater than or equal to 14 mol % and less than or equal to 17 mol %, or any and all sub-ranges formed from any of these endpoints. 
     B 2 O 3  decreases the melting point of the glass composition, which may improve the retention of certain colorants in the glass. B 2 O 3  may also improve the damage resistance of the resultant colored glass article. In addition, B 2 O 3  is added to reduce the formation of non-bridging oxygen, the presence of which may reduce fracture toughness. The concentration of B 2 O 3  should be sufficiently high (e.g., greater than or equal to 1 mol %) to reduce the melting point of the glass composition, improve the formability, and increase the fracture toughness of the colored glass article. However, if B 2 O 3  is too high (e.g., greater than 10 mol %), the annealing point and strain point may decrease, which increases stress relaxation and reduces the overall strength of the colored glass article. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 1 mol % and less than or equal to 10 mol % B 2 O 3 . In embodiments, the concentration of B 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to 1 mol %, greater than or equal to 2 mol %, greater than or equal to 3 mol %, greater than or equal to 4 mol %, greater than or equal to 4.5 mol %, greater than or equal to 5 mol %, or even greater than or equal to 5.5 mol %. In embodiments, the concentration of B 2 O 3  in the glass composition and the resultant colored glass article may be less than or equal to 10 mol %, less than or equal to 9 mol %, less than or equal to 8 mol %, less than or equal to 7.5 mol %, less than or equal to 7 mol %, or even less than or equal to 6.5 mol %. In embodiments, the concentration of B 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to 1 mol % and less than or equal to 10 mol %, greater than or equal to 1 mol % and less than or equal to 9 mol %, greater than or equal to 1 mol % and less than or equal to 8 mol %, greater than or equal to 1 mol % and less than or equal to 7.5 mol %, greater than or equal to 1 mol % and less than or equal to 7 mol %, greater than or equal to 1 mol % and less than or equal to 6.5 mol %, greater than or equal to 2 mol % and less than or equal to 10 mol %, greater than or equal to 2 mol % and less than or equal to 9 mol %, greater than or equal to 2 mol % and less than or equal to 8 mol %, greater than or equal to 2 mol % and less than or equal to 7.5 mol %, greater than or equal to 2 mol % and less than or equal to 7 mol %, greater than or equal to 2 mol % and less than or equal to 6.5 mol %, greater than or equal to 3 mol % and less than or equal to 10 mol %, greater than or equal to 3 mol % and less than or equal to 9 mol %, greater than or equal to 3 mol % and less than or equal to 8 mol %, greater than or equal to 3 mol % and less than or equal to 7.5 mol %, greater than or equal to 3 mol % and less than or equal to 7 mol %, greater than or equal to 3 mol % and less than or equal to 6.5 mol %, greater than or equal to 4 mol % and less than or equal to 10 mol %, greater than or equal to 4 mol % and less than or equal to 9 mol %, greater than or equal to 4 mol % and less than or equal to 8 mol %, greater than or equal to 4 mol % and less than or equal to 7.5 mol %, greater than or equal to 4 mol % and less than or equal to 7 mol %, greater than or equal to 4 mol % and less than or equal to 6.5 mol %, greater than or equal to 4.5 mol % and less than or equal to 10 mol %, greater than or equal to 4.5 mol % and less than or equal to 9 mol %, greater than or equal to 4.5 mol % and less than or equal to 8 mol %, greater than or equal to 4.5 mol % and less than or equal to 7.5 mol %, greater than or equal to 4.5 mol % and less than or equal to 7 mol %, greater than or equal to 4.5 mol % and less than or equal to 6.5 mol %, greater than or equal to 5 mol % and less than or equal to 10 mol %, greater than or equal to 5 mol % and less than or equal to 9 mol %, greater than or equal to 5 mol % and less than or equal to 8 mol %, greater than or equal to 5 mol % and less than or equal to 7.5 mol %, greater than or equal to 5 mol % and less than or equal to 7 mol %, greater than or equal to 5 mol % and less than or equal to 6.5 mol %, greater than or equal to 5.5 mol % and less than or equal to 10 mol %, greater than or equal to 5.5 mol % and less than or equal to 9 mol %, greater than or equal to 5.5 mol % and less than or equal to 8 mol %, greater than or equal to 5.5 mol % and less than or equal to 7.5 mol %, greater than or equal to 5.5 mol % and less than or equal to 7 mol %, or even greater than or equal to 5.5 mol % and less than or equal to 6.5 mol %, or any and all sub-ranges formed from any of these endpoints. 
     As described hereinabove, the glass compositions and the resultant colored glass articles may contain alkali oxides, such as Li 2 O, Na 2 O, and K 2 O, to enable the ion-exchangeability of the colored glass articles. 
     Li 2 O aids in the ion-exchangeability of the colored glass article and also reduces the softening point of the glass composition, thereby increasing the formability of the colored glass articles. In addition, Li 2 O decreases the melting point of the glass composition, which may help improve retention of colorants in the glass. The concentration of Li 2 O in the glass compositions and resultant colored glass articles should be sufficiently high (e.g., greater than or equal to 7 mol %) to reduce the melting point of the glass composition and achieve the desired maximum central tension (e.g., greater than or equal to 40 MPa). However, if the amount of Li 2 O is too high (e.g., greater than 14 mol %), the liquidus temperature may increase, thereby diminishing the manufacturability of the colored glass article. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 7 mol % and less than or equal to 14 mol % Li 2 O. In embodiments, the concentration of Li 2 O in the glass composition and the resultant colored glass article may be greater than or equal to 7 mol %, greater than or equal to 7.5 mol %, greater than or equal to 8 mol %, or even greater than or equal to 8.5 mol %. In embodiments, the concentration of Li 2 O in the glass composition and the resultant colored glass article may be less than or equal to 14 mol %, less than or equal to 13.5 mol %, less than or equal to 13 mol %, or even less than or equal to 12.5 mol %. In embodiments, the concentration of Li 2 O in the glass composition and the resultant colored glass article may be greater than or equal to 7 mol % and less than or equal to 14 mol %, greater than or equal to 7 mol % and less than or equal to 13.5 mol %, greater than or equal to 7 mol % and less than or equal to 13 mol %, greater than or equal to 7 mol % and less than or equal to 12.5 mol %, greater than or equal to 7.5 mol % and less than or equal to 14 mol %, greater than or equal to 7.5 mol % and less than or equal to 13.5 mol %, greater than or equal to 7.5 mol % and less than or equal to 13 mol %, greater than or equal to 7.5 mol % and less than or equal to 12.5 mol %, greater than or equal to 8 mol % and less than or equal to 14 mol %, greater than or equal to 8 mol % and less than or equal to 13.5 mol %, greater than or equal to 8 mol % and less than or equal to 13 mol %, greater than or equal to 8 mol % and less than or equal to 12.5 mol %, greater than or equal to 8.5 mol % and less than or equal to 14 mol %, greater than or equal to 8.5 mol % and less than or equal to 13.5 mol %, greater than or equal to 8.5 mol % and less than or equal to 13 mol %, or even greater than or equal to 8.5 mol % and less than or equal to 12.5 mol %, or any and all sub-ranges formed from any of these endpoints. 
     Na 2 O improves diffusivity of alkali ions in the glass and thereby reduces ion-exchange time and helps achieve the desired surface compressive stress (e.g., greater than or equal to 300 MPa). Na 2 O also improves formability of the colored glass article. In addition, Na 2 O decreases the melting point of the glass composition, which may help improve colorant retention. However, if too much Na 2 O is added to the glass composition, the melting point may be too low. As such, in embodiments, the concentration of Li 2 O present in the glass composition and the resultant colored glass article may be greater than the concentration of Na 2 O present in the glass composition and the resultant colored glass article. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than 0 mol % and less than or equal to 8 mol % Na 2 O. In embodiments, the concentration of Na 2 O in the glass composition and the resultant colored glass article may be greater than 0 mol %, greater than or equal to 0.1 mol %, greater than or equal to 0.5 mol %, or even greater than or equal to 1 mol %. In embodiments, the concentration of Na 2 O in the glass composition and the resultant colored glass article may be less than or equal to 8 mol %, less than or equal to 7 mol %, less than or equal to 6 mol %, less than or equal to 5 mol %, less than or equal to 4 mol %, or even less than or equal to 3 mol %, or any and all sub-ranges formed from any of these endpoints. In embodiments, the concentration of Na 2 O in the glass composition and the resultant colored glass article may be greater than 0 mol % and less than or equal to 8 mol %, greater than 0 mol % and less than or equal to 7 mol %, greater than 0 mol % and less than or equal to 6 mol %, greater than 0 mol % and less than or equal to 5 mol %, greater than 0 mol % and less than or equal to 4 mol %, greater than 0 mol % and less than or equal to 3 mol %, greater than or equal to 0.1 mol % and less than or equal to 8 mol %, greater than or equal to 0.1 mol % and less than or equal to 7 mol %, greater than or equal to 0.1 mol % and less than or equal to 6 mol %, greater than or equal to 0.1 mol % and less than or equal to 5 mol %, greater than or equal to 0.1 mol % and less than or equal to 4 mol %, greater than or equal to 0.1 mol % and less than or equal to 3 mol %, greater than or equal to 0.5 mol % and less than or equal to 8 mol %, greater than or equal to 0.5 mol % and less than or equal to 7 mol %, greater than or equal to 0.5 mol % and less than or equal to 6 mol %, greater than or equal to 0.5 mol % and less than or equal to 5 mol %, greater than or equal to 0.5 mol % and less than or equal to 4 mol %, greater than or equal to 0.5 mol % and less than or equal to 3 mol %, greater than or equal to 1 mol % and less than or equal to 8 mol %, greater than or equal to 1 mol % and less than or equal to 7 mol %, greater than or equal to 1 mol % and less than or equal to 6 mol %, greater than or equal to 1 mol % and less than or equal to 5 mol %, greater than or equal to 1 mol % and less than or equal to 4 mol %, or even greater than or equal to 1 mol % and less than or equal to 3 mol %, or any and all sub-ranges formed from any of these endpoints. 
     K 2 O promotes ion-exchange and may increase the depth of compression and decrease the melting point to improve the formability of the colored glass article. However, adding too much K 2 O may cause the surface compressive stress and melting point to be too low. Accordingly, in embodiments, the amount of K 2 O added to the glass composition may be limited. 
     In embodiments, the glass composition and the resultant colored glass article may optionally comprise greater than 0 mol % and less than or equal to 1 mol % K 2 O. In embodiments, the concentration of K 2 O in the glass composition and the resultant colored glass article may be greater than 0 mol %, greater than or equal to 0.1 mol %, or even greater than or equal to 0.2 mol %. In embodiments, the concentration of K 2 O in the glass composition and the resultant colored glass article may be less than or equal to 1 mol %, less than or equal to 0.7 mol %, or even less than or equal to 0.5 mol %. In embodiments, the concentration of K 2 O in the glass composition and the resultant colored glass article may be greater than 0 mol % and less than or equal to 1 mol %, greater than 0 mol % and less than or equal to 0.7 mol %, greater than 0 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 1 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.7 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 1 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.7 mol %, or even greater than or equal to 0.2 mol % and less than or equal to 0.5 mol %, or any and all sub-ranges formed from any of these endpoints. 
     R 2 O is the sum (in mol %) of Li 2 O, Na 2 O, and K 2 O present in the glass composition and the resultant colored glass article (i.e., R 2 O=Li 2 O (mol %)+Na 2 O (mol %)+K 2 O (mol %). Like B 2 O 3 , the alkali oxides aid in decreasing the softening point and molding temperature of the glass composition, thereby offsetting the increase in the softening point and molding temperature of the glass composition due to higher amounts of SiO 2  in the glass composition, for example. The softening point and molding temperature may be further reduced by including combinations of alkali oxides (e.g., two or more alkali oxides) in the glass composition, a phenomenon referred to as the “mixed alkali effect.” However, it has been found that if the amount of R 2 O is too high, the average coefficient of thermal expansion of the glass composition increases to greater than 100×10 −7 /° C., which may be undesirable. 
     In embodiments, the concentration of R 2 O in the glass composition and the resultant colored glass article may be greater than or equal to 7 mol %, greater than or equal to 8 mol %, greater than 9 mol %, or even greater than or equal to 10 mol %. In embodiments, the concentration of R 2 O in the glass composition and the resultant colored glass article may be less than or equal to 25 mol %, less than or equal to 23 mol %, or even less than or equal to 20 mol %. In embodiments, the concentration of R 2 O in the glass composition and the resultant colored glass article may be greater than or equal to 7 mol % and less than or equal to 25 mol %, greater than or equal to 7 mol % and less than or equal to 23 mol %, greater than or equal to 7 mol % and less than or equal to 20 mol %, greater than or equal to 8 mol % and less than or equal to 25 mol %, greater than or equal to 8 mol % and less than or equal to 23 mol %, greater than or equal to 8 mol % and less than or equal to 20 mol %, greater than or equal to 9 mol % and less than or equal to 25 mol %, greater than or equal to 9 mol % and less than or equal to 23 mol %, greater than or equal to 9 mol % and less than or equal to 20 mol %, greater than or equal to 10 mol % and less than or equal to 25 mol %, greater than or equal to 10 mol % and less than or equal to 23 mol %, or even greater than or equal to 10 mol % and less than or equal to 20 mol %, or any and all sub-ranges formed from any of these endpoints. 
     In embodiments, the difference between R 2 O and Al 2 O 3  (i.e. R 2 O (mol %)-Al 2 O 3  (mol %)) in the glass composition may be adjusted to reduce the formation of non-bridging oxygen, the presence of which may reduce fracture toughness. In embodiments, R 2 O−Al 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to −8 mol %, greater than or equal to −7, greater than or equal to −6, or even greater than or equal to −5. In embodiments, R 2 O−Al 2 O 3  in the glass composition and the resultant colored glass article may be less than or equal to 4 mol %, less than or equal to 3 mol %, less than or equal to 2 mol %, or even less than or equal to 1 mol %. In embodiments, R 2 O−Al 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to −8 mol % and less than or equal to 4 mol %, greater than or equal to −8 mol % and less than or equal to 3 mol %, greater than or equal to −8 mol % and less than or equal to 2 mol %, greater than or equal to −8 mol % and less than or equal to 1 mol %, greater than or equal to −7 mol % and less than or equal to 4 mol %, greater than or equal to −7 mol % and less than or equal to 3 mol %, greater than or equal to −7 mol % and less than or equal to 2 mol %, greater than or equal to −7 mol % and less than or equal to 1 mol %, greater than or equal to −6 mol % and less than or equal to 4 mol %, greater than or equal to −6 mol % and less than or equal to 3 mol %, greater than or equal to −6 mol % and less than or equal to 2 mol %, greater than or equal to −6 mol % and less than or equal to 1 mol %, greater than or equal to −5 mol % and less than or equal to 4 mol %, greater than or equal to −5 mol % and less than or equal to 3 mol %, greater than or equal to −5 mol % and less than or equal to 2 mol %, or even greater than or equal to −5 mol % and less than or equal to 1 mol %, or any and all sub-ranges formed from any of these endpoints. 
     In embodiments, the glass compositions and the resultant colored glass articles described herein may further comprise CaO. CaO lowers the viscosity of a glass composition, which enhances the formability, the strain point and the Young&#39;s modulus, and may improve the ion-exchangeability. However, when too much CaO is added to the glass composition, the diffusivity of sodium and potassium ions in the glass composition decreases which, in turn, adversely impacts the ion-exchange performance (i.e., the ability to ion-exchange) of the resultant glass. 
     In embodiments, the concentration of CaO in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol %, greater than or equal to 0.25 mol %, greater than or equal to 0.5 mol %, or even greater than or equal to 0.75 mol %. In embodiments, the concentration of CaO in the glass composition and the resultant colored glass article may be less than or equal to 7 mol %, less than or equal to 6.5 mol %, less than or equal to 6 mol %, less than or equal to 5.5 mol %, less than or equal to 5 mol %, less than or equal to 4.5 mol %, less than or equal to 4 mol %, less than or equal to 3.5 mol %, less than or equal to 3 mol %, less than or equal to 2.5 mol %, less than or equal to 2 mol %, or even less than or equal to 1.75 mol %. In embodiments, the concentration of CaO in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % and less than or equal to 7 mol %, greater than or equal to 0 mol % and less than or equal to 6.5 mol %, greater than or equal to 0 mol % and less than or equal to 6 mol %, greater than or equal to 0 mol % and less than or equal to 5.5 mol %, greater than or equal to 0 mol % and less than or equal to 5 mol %, greater than or equal to 0 mol % and less than or equal to 4.5 mol %, greater than or equal to 0 mol % and less than or equal to 4 mol %, greater than or equal to 0 mol % and less than or equal to 3.5 mol %, greater than or equal to 0 mol % and less than or equal to 3 mol %, greater than or equal to 0 mol % and less than or equal to 2.5 mol %, greater than or equal to 0 mol % and less than or equal to 2 mol %, greater than or equal to 0 mol % and less than or equal to 1.75 mol %, greater than or equal to 0.25 mol % and less than or equal to 7 mol %, greater than or equal to 0.25 mol % and less than or equal to 6.5 mol %, greater than or equal to 0.25 mol % and less than or equal to 6 mol %, greater than or equal to 0.25 mol % and less than or equal to 5.5 mol %, greater than or equal to 0.25 mol % and less than or equal to 5 mol %, greater than or equal to 0.25 mol % and less than or equal to 4.5 mol %, greater than or equal to 0.25 mol % and less than or equal to 4 mol %, greater than or equal to 0.25 mol % and less than or equal to 3.5 mol %, greater than or equal to 0.25 mol % and less than or equal to 3 mol %, greater than or equal to 0.25 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.25 mol % and less than or equal to 2 mol %, greater than or equal to 0.25 mol % and less than or equal to 1.75 mol %, greater than or equal to 0.5 mol % and less than or equal to 7 mol %, greater than or equal to 0.5 mol % and less than or equal to 6.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 6 mol %, greater than or equal to 0.5 mol % and less than or equal to 5.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 5 mol %, greater than or equal to 0.5 mol % and less than or equal to 4.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 4 mol %, greater than or equal to 0.5 mol % and less than or equal to 3.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 3 mol %, greater than or equal to 0.5 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 2 mol %, greater than or equal to 0.5 mol % and less than or equal to 1.75 mol %, greater than or equal to 0.75 mol % and less than or equal to 7 mol %, greater than or equal to 0.75 mol % and less than or equal to 6.5 mol %, greater than or equal to 0.75 mol % and less than or equal to 6 mol %, greater than or equal to 0.75 mol % and less than or equal to 5.5 mol %, greater than or equal to 0.75 mol % and less than or equal to 5 mol %, greater than or equal to 0.75 mol % and less than or equal to 4.5 mol %, greater than or equal to 0.75 mol % and less than or equal to 4 mol %, greater than or equal to 0.75 mol % and less than or equal to 3.5 mol %, greater than or equal to 0.75 mol % and less than or equal to 3 mol %, greater than or equal to 0.75 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.75 mol % and less than or equal to 2 mol %, or even greater than or equal to 0.75 mol % and less than or equal to 1.75 mol %, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant colored glass article may be substantially free or free of CaO. 
     In embodiments, the glass compositions and the resultant colored glass articles described herein may further comprise MgO. MgO lowers the viscosity of the glass compositions, which enhances the formability, the strain point, and the Young&#39;s modulus, and may improve ion-exchangeability. However, when too much MgO is added to the glass composition, the diffusivity of sodium and potassium ions in the glass composition decreases which, in turn, adversely impacts the ion-exchange performance (i.e., the ability to ion-exchange) of the resultant colored glass article. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0 mol % and less than or equal to 8 mol % MgO. In embodiments, the concentration of MgO in the glass composition may be greater than or equal to 0 mol %, greater than or equal to 0.5 mol %, greater than or equal to 1 mol %, or even greater than or equal to 1.5 mol %. In embodiments, the concentration of MgO in the glass composition may be less than or equal to 8 mol %, less than or equal to 7 mol %, less than or equal to 6 mol %, less than or equal to 5.5 mol %, less than or equal to 5 mol %, less than or equal to 4.5 mol %, or even less than or equal to 4 mol %. In embodiments, the concentration of MgO in the glass composition may be greater than or equal to 0 mol % and less than or equal to 8 mol %, greater than or equal to 0 mol % and less than or equal to 7 mol %, greater than or equal to 0 mol % and less than or equal to 6 mol %, greater than or equal to 0 mol % and less than or equal to 5.5 mol %, greater than or equal to 0 mol % and less than or equal to 5 mol %, greater than or equal to 0 mol % and less than or equal to 4.5 mol %, greater than or equal to 0 mol % and less than or equal to 4 mol %, greater than or equal to 0.5 mol % and less than or equal to 8 mol %, greater than or equal to 0.5 mol % and less than or equal to 7 mol %, greater than or equal to 0.5 mol % and less than or equal to 6 mol %, greater than or equal to 0.5 mol % and less than or equal to 5.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 5 mol %, greater than or equal to 0.5 mol % and less than or equal to 4.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 4 mol %, greater than or equal to 1 mol % and less than or equal to 8 mol %, greater than or equal to 1 mol % and less than or equal to 7 mol %, greater than or equal to 1 mol % and less than or equal to 6 mol %, greater than or equal to 1 mol % and less than or equal to 5.5 mol %, greater than or equal to 1 mol % and less than or equal to 5 mol %, greater than or equal to 1 mol % and less than or equal to 4.5 mol %, greater than or equal to 1 mol % and less than or equal to 4 mol %, greater than or equal to 1.5 mol % and less than or equal to 8 mol %, greater than or equal to 1.5 mol % and less than or equal to 7 mol %, greater than or equal to 1.5 mol % and less than or equal to 6 mol %, greater than or equal to 1.5 mol % and less than or equal to 5.5 mol %, greater than or equal to 1.5 mol % and less than or equal to 5 mol %, greater than or equal to 1.5 mol % and less than or equal to 4.5 mol %, or even greater than or equal to 1.5 mol % and less than or equal to 4 mol %, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant colored glass article may be substantially free or free of MgO. 
     In embodiments, the glass compositions and the resultant colored glass articles described herein may further comprise ZnO. ZnO lowers the viscosity of the glass compositions, which enhances the formability, the strain point, and the Young&#39;s modulus, and may improve ion-exchangeability. However, when too much ZnO is added to the glass composition, the diffusivity of sodium and potassium ions in the glass composition decreases which, in turn, adversely impacts the ion-exchange performance (i.e., the ability to ion-exchange) of the resultant colored glass article. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0 mol % and less than or equal to 8 mol % ZnO. In embodiments, the concentration of ZnO in the glass composition may be greater than or equal to 0 mol %, greater than or equal to 0.5 mol %, greater than or equal to 1 mol %, or even greater than or equal to 1.5 mol %. In embodiments, the concentration of ZnO in the glass composition may be less than or equal to 8 mol %, less than or equal to 7 mol %, less than or equal to 6 mol %, less than or equal to 5.5 mol %, less than or equal to 5 mol %, less than or equal to 4.5 mol %, or even less than or equal to 4 mol %. In embodiments, the concentration of ZnO in the glass composition may be greater than or equal to 0 mol % and less than or equal to 8 mol %, greater than or equal to 0 mol % and less than or equal to 7 mol %, greater than or equal to 0 mol % and less than or equal to 6 mol %, greater than or equal to 0 mol % and less than or equal to 5.5 mol %, greater than or equal to 0 mol % and less than or equal to 5 mol %, greater than or equal to 0 mol % and less than or equal to 4.5 mol %, greater than or equal to 0 mol % and less than or equal to 4 mol %, greater than or equal to 0.5 mol % and less than or equal to 8 mol %, greater than or equal to 0.5 mol % and less than or equal to 7 mol %, greater than or equal to 0.5 mol % and less than or equal to 6 mol %, greater than or equal to 0.5 mol % and less than or equal to 5.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 5 mol %, greater than or equal to 0.5 mol % and less than or equal to 4.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 4 mol %, greater than or equal to 1 mol % and less than or equal to 8 mol %, greater than or equal to 1 mol % and less than or equal to 7 mol %, greater than or equal to 1 mol % and less than or equal to 6 mol %, greater than or equal to 1 mol % and less than or equal to 5.5 mol %, greater than or equal to 1 mol % and less than or equal to 5 mol %, greater than or equal to 1 mol % and less than or equal to 4.5 mol %, greater than or equal to 1 mol % and less than or equal to 4 mol %, greater than or equal to 1.5 mol % and less than or equal to 8 mol %, greater than or equal to 1.5 mol % and less than or equal to 7 mol %, greater than or equal to 1.5 mol % and less than or equal to 6 mol %, greater than or equal to 1.5 mol % and less than or equal to 5.5 mol %, greater than or equal to 1.5 mol % and less than or equal to 5 mol %, greater than or equal to 1.5 mol % and less than or equal to 4.5 mol %, or even greater than or equal to 1.5 mol % and less than or equal to 4 mol %, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant colored glass article may be substantially free or free of ZnO. 
     R′O is the sum (in mol %) of CaO, MgO, and ZnO present in the glass composition and the resultant colored glass article (i.e., R′O=CaO (mol %)+MgO (mol %)+ZnO (mol %)). In embodiments, the concentration of R′O in the glass composition and the resultant colored glass article may be greater than or equal 0 mol %, greater than or equal to 0.5 mol %, greater than or equal to 1 mol %, greater than or equal to 2 mol %, greater than or equal to 3 mol %, or even greater than or equal to 4 mol %. In embodiments, the concentration of R′O in the glass composition and the resultant colored glass article may be less than or equal to 12 mol %, less than or equal to 10 mol %, less than or equal to 8 mol %, or even less than or equal to 6 mol %. In embodiments, the concentration of R′O in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % and less than or equal to 12 mol %, greater than or equal to 0 mol % and less than or equal to 10 mol %, greater than or equal to 0 mol % and less than or equal to 8 mol %, greater than or equal to 0 mol % and less than or equal to 6 mol %, greater than or equal to 0.5 mol % and less than or equal to 12 mol %, greater than or equal to 0.5 mol % and less than or equal to 10 mol %, greater than or equal to 0.5 mol % and less than or equal to 8 mol %, greater than or equal to 0.5 mol % and less than or equal to 6 mol %, greater than or equal to 1 mol % and less than or equal to 12 mol %, greater than or equal to 1 mol % and less than or equal to 10 mol %, greater than or equal to 1 mol % and less than or equal to 8 mol %, greater than or equal to 1 mol % and less than or equal to 6 mol %, greater than or equal to 2 mol % and less than or equal to 12 mol %, greater than or equal to 2 mol % and less than or equal to 10 mol %, greater than or equal to 2 mol % and less than or equal to 8 mol %, greater than or equal to 2 mol % and less than or equal to 6 mol %, greater than or equal to 3 mol % and less than or equal to 12 mol %, greater than or equal to 3 mol % and less than or equal to 10 mol %, greater than or equal to 3 mol % and less than or equal to 8 mol %, greater than or equal to 3 mol % and less than or equal to 6 mol %, greater than or equal to 4 mol % and less than or equal to 12 mol %, greater than or equal to 4 mol % and less than or equal to 10 mol %, greater than or equal to 4 mol % and less than or equal to 8 mol %, or even greater than or equal to 4 mol % and less than or equal to 6 mol %, or any and all sub-ranged formed from any of these endpoints. 
     As described herein, the sum of R 2 O and R′O (i.e., R 2 O (mol %)+R′O (mol %)) may be relatively low (e.g., less than or equal to 25 mol %) to achieve a reduced dielectric constant (e.g., less than or equal to 6.8), thereby allowing for use of the colored glass article in high frequency applications. In embodiments, R 2 O+R′O in the glass composition and the resultant colored glass article may be greater than or equal to 7 mol %, greater than or equal to 9 mol %, greater than or equal to 11 mol %, greater than or equal to 13 mol %, or even greater than or equal to 15 mol %. In embodiments, R 2 O+R′O in the glass composition and the resultant colored glass article may be less than or equal to 25 mol %, less than or equal to 23 mol %, less than or equal to 20 mol %, or even less than or equal to 18 mol %. In embodiments, R 2 O+R′O in the glass composition and the resultant colored glass article may be greater than or equal to 7 mol % and less than or equal to 25 mol %, greater than or equal to 7 mol % and less than or equal to 23 mol %, greater than or equal to 7 mol % and less than or equal to 20 mol %, greater than or equal to 7 mol % and less than or equal to 18 mol %, greater than or equal to 9 mol % and less than or equal to 25 mol %, greater than or equal to 9 mol % and less than or equal to 23 mol %, greater than or equal to 9 mol % and less than or equal to 20 mol %, greater than or equal to 9 mol % and less than or equal to 18 mol %, greater than or equal to 11 mol % and less than or equal to 25 mol %, greater than or equal to 11 mol % and less than or equal to 23 mol %, greater than or equal to 11 mol % and less than or equal to 20 mol %, greater than or equal to 11 mol % and less than or equal to 18 mol %, greater than or equal to 13 mol % and less than or equal to 25 mol %, greater than or equal to 13 mol % and less than or equal to 23 mol %, greater than or equal to 13 mol % and less than or equal to 20 mol %, greater than or equal to 13 mol % and less than or equal to 18 mol %, greater than or equal to 15 mol % and less than or equal to 25 mol %, greater than or equal to 15 mol % and less than or equal to 23 mol %, greater than or equal to 15 mol % and less than or equal to 20 mol %, or even greater than or equal to 15 mol % and less than or equal to 18 mol %, or any and all sub-ranges formed from any of these endpoints. 
     The glass compositions and the resultant colored glass articles described herein may further comprise Fe 2 O 3 , which may help improve colorant retention. Fe 2 O 3  may also act as a colorant, producing colored glass articles that may, for example, be pink in color. In embodiments, the concentration of Fe 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % or even greater than or equal to 0.01 mol %. In embodiments, the concentration of Fe 2 O 3  in the glass composition and the resultant colored glass article may be less than or equal to 1 mol %, less than or equal to 0.75 mol %, or even less than or equal to 0.5 mol %. In embodiments, the concentration of Fe 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % and less than or equal to 1 mol %, greater than or equal to 0 mol % and less than or equal to 0.75 mol %, greater than or equal to 0 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.01 mol % and less than or equal to 1 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.75 mol %, or even greater than or equal to 0.01 mol % and less than or equal to 0.5 mol %, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant colored glass article may be substantially free or free of Fe 2 O 3 . 
     In embodiments, the concentration of Fe 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol %, greater than or equal to 0.001 mol %, or even greater than or equal to 0.005 mol %. In embodiment, the concentration of Fe 2 O 3  in the glass composition and the resultant colored glass article may be less than or equal to 0.5 mol %, less than or equal to 0.1 mol %, less than or equal to 0.05 mol %, or even less than or equal to 0.01 mol %. In embodiments, the composition and the resultant colored glass article may be greater than or equal to 0 mol % and less than or equal to 0.5 mol %, greater than or equal to 0 mol % and less than or equal to 0.1 mol %, greater than or equal to 0 mol % and less than or equal to 0.05 mol %, greater than or equal to 0 mol % and less than or equal to 0.01 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.1 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.05 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.01 mol %, greater than or equal to 0.005 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.005 mol % and less than or equal to 0.1 mol %, greater than or equal to 0.005 mol % and less than or equal to 0.05 mol %, or even greater than or equal to 0.005 mol % and less than or equal to 0.01 mol %, or any and all sub-ranges formed from any of these endpoints. 
     The glass compositions and the resultant colored glass articles described herein may further comprise SnO 2 . In embodiments, the concentration of SnO 2  in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % or even greater than or equal to 0.01 mol %. In embodiments, the concentration of SnO 2  in the glass composition and the resultant colored glass article may be less than or equal to 1 mol %, less than or equal to 0.75 mol %, less than or equal to 0.5 mol %, or even less than or equal to 0.25 mol %. In embodiments, the concentration of SnO 2  in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % and less than or equal to 1 mol %, greater than or equal to 0 mol % and less than or equal to 0.75 mol %, greater than or equal to 0 mol % and less than or equal to 0.5 mol %, greater than or equal to 0 mol % and less than or equal to 0.25 mol %, greater than or equal to 0.01 mol % and less than or equal to 1 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.5 mol %, or even greater than or equal to 0.01 mol % and less than or equal to 0.25 mol %, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant colored glass article may be substantially free or free of SnO 2 . 
     In embodiments, the glass compositions and the resultant colored glass articles may include a colorant that comprises or consists of transition metal oxides, rare earth oxides, or combinations thereof, to achieve a desired color. In embodiments, transition metal oxides and/or rare earth oxides may be included in the glass compositions as the sole colorant or in combination with other colorants. In embodiments, colorants based on transition metal oxides and/or rare earth oxides may include NiO, Co 3 O 4 , Cr 2 O 3 , CuO, CeO 2 , TiO 2  and/or combinations thereof. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0.001 mol %, such as greater than or equal to 0.001 mol % and less than or equal to 10 mol %, NiO+Co 3 O 4 +Cr 2 O 3 +CuO+CeO 2 +TiO 2 . In embodiments, the concentration of NiO+Co 3 O 4 +Cr 2 O 3 +CuO+CeO 2 +TiO 2  in the glass composition and the resultant colored glass article may be greater than or equal to 0.001 mol % and less than or equal to 5 mol %, greater than or equal to 0.001 mol % and less than or equal to 4 mol %, greater than or equal to 0.001 mol % and less than or equal to 3 mol %, greater than or equal to 0.001 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.001 mol % and less than or equal to 2 mol %, greater than or equal to 0.001 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.01 mol % and less than or equal to 5 mol %, greater than or equal to 0.01 mol % and less than or equal to 4 mol %, greater than or equal to 0.01 mol % and less than or equal to 3 mol %, greater than or equal to 0.01 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.01 mol % and less than or equal to 2 mol %, greater than or equal to 0.01 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.02 mol % and less than or equal to 5 mol %, greater than or equal to 0.02 mol % and less than or equal to 4 mol %, greater than or equal to 0.02 mol % and less than or equal to 3 mol %, greater than or equal to 0.02 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.02 mol % and less than or equal to 2 mol %, greater than or equal to 0.02 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 5 mol %, greater than or equal to 0.1 mol % and less than or equal to 4 mol %, greater than or equal to 0.1 mol % and less than or equal to 3 mol %, greater than or equal to 0.1 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 2 mol %, greater than or equal to 0.1 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 5 mol %, greater than or equal to 0.5 mol % and less than or equal to 4 mol %, greater than or equal to 0.5 mol % and less than or equal to 3 mol %, greater than or equal to 0.5 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.5 mol % and less than or equal to 2 mol %, greater than or equal to 0.5 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.7 mol % and less than or equal to 5 mol %, greater than or equal to 0.7 mol % and less than or equal to 4 mol %, greater than or equal to 0.7 mol % and less than or equal to 3 mol %, greater than or equal to 0.7 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.7 mol % and less than or equal to 2 mol %, greater than or equal to 0.7 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.9 mol % and less than or equal to 5 mol %, greater than or equal to 0.9 mol % and less than or equal to 4 mol %, greater than or equal to 0.9 mol % and less than or equal to 3 mol %, greater than or equal to 0.9 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.9 mol % and less than or equal to 2 mol %, greater than or equal to 0.9 mol % and less than or equal to 1.5 mol %, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and resultant glass article may comprise 0 mol % of one or more of NiO, Co 3 O 4 , Cr 2 O 3 , CuO, CeO 2 , and/or TiO 2 . 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0.001 mol %, such as greater than or equal to 0.001 mol % and less than or equal to 3 mol %, NiO+Co 3 O 4 +Cr 2 O 3 +CuO. In embodiments, the concentration of NiO+Co 3 O 4 +Cr 2 O 3 +CuO in the glass composition and the resultant colored glass article may be greater than or equal to 0.001 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.001 mol % and less than or equal to 2 mol %, greater than or equal to 0.001 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.001 mol % and less than or equal to 1 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.01 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.01 mol % and less than or equal to 2 mol %, greater than or equal to 0.01 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.01 mol % and less than or equal to 1 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.02 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.02 mol % and less than or equal to 2 mol %, greater than or equal to 0.02 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.02 mol % and less than or equal to 1 mol %, greater than or equal to 0.02 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.02 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.1 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 2 mol %, greater than or equal to 0.1 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 1 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.2 mol % and less than or equal to 2.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 2 mol %, greater than or equal to 0.2 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 1 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.4 mol %, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and resultant glass article may comprise 0 mol % of one or more of NiO, Co 3 O 4 , Cr 2 O 3 , and/or CuO. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0.1 mol %, such as greater than or equal to 0.1 mol % and less than or equal to 2 mol %, CeO 2 . In embodiments, the concentration of CeO 2  in the glass composition and the resultant colored glass article may be greater than or equal to 0.1 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 1 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.2 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 1 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.3 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.3 mol % and less than or equal to 1 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.4 mol %, or any and all sub-ranges formed from any of these endpoints. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0.1 mol %, such as greater than or equal to 0.1 mol % and less than or equal to 2 mol %, TiO 2 . In embodiments, the concentration of TiO 2  in the glass composition and the resultant colored glass article may be greater than or equal to 0.1 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 1 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.2 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 1 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.3 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.3 mol % and less than or equal to 1 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.4 mol %, or any and all sub-ranges formed from any of these endpoints. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0.1 mol %, such as greater than or equal to 0.1 mol % and less than or equal to 2 mol %, CeO 2 +TiO 2 . In embodiments, the concentration of CeO 2 +TiO 2  in the glass composition and the resultant colored glass article may be greater than or equal to 0.1 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 1 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.2 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 1 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.2 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.3 mol % and less than or equal to 1.5 mol %, greater than or equal to 0.3 mol % and less than or equal to 1 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.75 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.3 mol % and less than or equal to 0.4 mol %, or any and all sub-ranges formed from any of these endpoints. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0 mol %, such as greater than or equal to 0.01 mol % and less than or equal to 0.05 mol %, NiO. In embodiments, the concentration of NiO in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % and less than or equal to 0.05 mol %, greater than or equal to 0 mol % and less than or equal to 0.04 mol %, greater than or equal to 0 mol % and less than or equal to 0.035 mol %, greater than or equal to 0 mol % and less than or equal to 0.03 mol %, greater than or equal to 0 mol % and less than or equal to 0.025 mol %, greater than or equal to 0 mol % and less than or equal to 0.02 mol %, greater than or equal to 0 mol % and less than or equal to 0.015 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.05 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.04 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.035 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.03 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.025 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.02 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.015 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.05 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.04 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.035 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.03 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.025 mol %, or even greater than or equal to 0.015 mol % and less than or equal to 0.02 mol %, and all sub-ranges formed from any of these endpoints. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0 mol %, such as greater than or equal to 0.1 mol % and less than or equal to 0.5 mol %, CuO. In embodiments, the concentration of CuO in the glass composition and the resultant colored glass article may be greater than or equal to 0.1 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.35 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.3 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.25 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.2 mol %, greater than or equal to 0.1 mol % and less than or equal to 0.15 mol %, greater than or equal to 0.15 mol % and less than or equal to 0.5 mol %, greater than or equal to 0.15 mol % and less than or equal to 0.4 mol %, greater than or equal to 0.15 mol % and less than or equal to 0.35 mol %, greater than or equal to 0.15 mol % and less than or equal to 0.3 mol %, greater than or equal to 0.15 mol % and less than or equal to 0.25 mol %, or even greater than or equal to 0.15 mol % and less than or equal to 0.2 mol %, and all sub-ranges formed from any of these endpoints. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0 mol %, such as greater than or equal to 0.0001 mol % and less than or equal to 0.01 mol %, Co 3 O 4 . In embodiments, the concentration of Co 3 O 4  in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % and less than or equal to 0.01 mol %, greater than or equal to 0 mol % and less than or equal to 0.0095 mol %, greater than or equal to 0 mol % and less than or equal to 0.009 mol %, greater than or equal to 0 mol % and less than or equal to 0.0085 mol %, greater than or equal to 0 mol % and less than or equal to 0.0075 mol %, greater than or equal to 0 mol % and less than or equal to 0.007 mol %, greater than or equal to 0 mol % and less than or equal to 0.0065 mol %, greater than or equal to 0 mol % and less than or equal to 0.006 mol %, greater than or equal to 0 mol % and less than or equal to 0.0055 mol %, greater than or equal to 0 mol % and less than or equal to 0.005 mol %, greater than or equal to 0 mol % and less than or equal to 0.0045 mol %, greater than or equal to 0 mol % and less than or equal to 0.004 mol %, greater than or equal to 0 mol % and less than or equal to 0.0035 mol %, greater than or equal to 0 mol % and less than or equal to 0.003 mol %, greater than or equal to 0 mol % and less than or equal to 0.0025 mol %, greater than or equal to 0 mol % and less than or equal to 0.002 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.01 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.0095 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.009 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.0085 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.0075 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.007 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.0065 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.006 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.0055 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.005 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.0045 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.004 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.0035 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.003 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.0025 mol %, greater than or equal to 0.0001 mol % and less than or equal to 0.002 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.01 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.0095 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.009 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.0085 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.0075 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.007 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.0065 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.006 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.0055 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.005 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.0045 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.004 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.0035 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.003 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.0025 mol %, greater than or equal to 0.001 mol % and less than or equal to 0.002 mol %, and all sub-ranges formed from any of these endpoints. 
     In embodiments, the glass composition and the resultant colored glass article may comprise greater than or equal to 0 mol %, such as greater than or equal to 0.01 mol % and less than or equal to 0.05 mol %, Cr 2 O 3 . In embodiments, the concentration of Cr 2 O 3  in the glass composition and the resultant colored glass article may be greater than or equal to 0 mol % and less than or equal to 0.05 mol %, greater than or equal to 0 mol % and less than or equal to 0.04 mol %, greater than or equal to 0 mol % and less than or equal to 0.035 mol %, greater than or equal to 0 mol % and less than or equal to 0.03 mol %, greater than or equal to 0 mol % and less than or equal to 0.025 mol %, greater than or equal to 0 mol % and less than or equal to 0.02 mol %, greater than or equal to 0 mol % and less than or equal to 0.015 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.05 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.04 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.035 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.03 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.025 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.02 mol %, greater than or equal to 0.01 mol % and less than or equal to 0.015 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.05 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.04 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.035 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.03 mol %, greater than or equal to 0.015 mol % and less than or equal to 0.025 mol %, or even greater than or equal to 0.015 mol % and less than or equal to 0.02 mol %, and all sub-ranges formed from any of these endpoints. 
     In embodiments, the glass composition and the resultant colored glass article may comprise at least one of: greater than or equal to 0.001 mol % NiO+Co 3 O 4 +Cr 2 O 3 +CuO, such as greater than or equal to 0.001 mol % and less than or equal to 3 mol % NiO+Co 3 O 4 +Cr 2 O 3 +CuO (or any of the ranges of NiO+Co 3 O 4 +Cr 2 O 3 +CuO described herein); greater than or equal to 0.1 mol % CeO 2 , such as greater than or equal to 0.1 mol % and less than or equal to 1.5 mol % CeO 2  (or any of the ranges of CeO 2  described herein); and greater than or equal to 0.1 mol % TiO 2 , such as greater than or equal to 0.1 mol % and less than or equal to 2 mol % TiO 2  (or any of the ranges of TiO 2  described herein). 
     In embodiments, the glass compositions and the resultant colored glass articles described herein may further include tramp materials such as MnO, MoO 3 , WO 3 , Y 2 O 3 , CdO, As 2 O 3 , sulfur-based compounds, such as sulfates, halogens, or combinations thereof. In embodiments, the glass composition and the resultant colored glass article may be substantially free or free of tramp materials such as MnO, MoO 3 , WO 3 , Y 2 O 3 , CdO, As 2 O 3 , sulfur-based compounds, such as sulfates, halogens, or combinations thereof. 
     In embodiments, the process for making a glass article includes heat treating a glass composition described herein at one or more preselected temperatures for one or more preselected times to induce glass homogenization. In embodiments, the heat treatment for making a glass article may include heating a glass composition at a rate of 1-100° C./min to glass homogenization temperature; (ii) maintaining the glass composition at the glass homogenization temperature for a time greater than or equal to 0.25 hour and less than or equal to 40 hours (such as 0.25 hours to 4 hours) to produce a glass article; and cooling the glass composition to room temperature to form the glass article to room temperature. In embodiments, the glass homogenization temperature may be greater than or equal to 300° C. and less than or equal to 700° C. In embodiments, the formed glass article may be a colored glass article such that additional heat treatment is not necessary. In embodiments, the colored glass article may be produced when heating above a certain temperature (e.g., the glass homogenation temperature) such that the maintaining step is not required to produce the colored glass article. 
     As described herein, the sum of R 2 O and R′O (i.e., R 2 O (mol %)+R′O (mol %)) may be relatively low (e.g., less than or equal to 25 mol %) to achieve a reduced dielectric constant (e.g., less than or equal to 6.8), thereby allowing for use of the colored glass article in high frequency applications. In embodiments, the colored glass articles described herein may have a dielectric constant Dk at 10 GHz less than or equal to 6.8, such as less than or equal to 6.8 and greater than or equal to 5.6. In embodiments, the dielectric constant of the colored glass article may be less than or equal to 6.8 and greater than or equal to 5.7, less than or equal to 6.8 and greater than or equal to 5.8, less than or equal to 6.8 and greater than or equal to 5.9, less than or equal to 6.8 and greater than or equal to 6.0, less than or equal to 6.8 and greater than or equal to 6.2, less than or equal to 6.6 and greater than or equal to 5.7, less than or equal to 6.6 and greater than or equal to 5.8, less than or equal to 6.6 and greater than or equal to 5.9, less than or equal to 6.6 and greater than or equal to 6.0, less than or equal to 6.6 and greater than or equal to 6.2, less than or equal to 6.4 and greater than or equal to 5.7, less than or equal to 6.4 and greater than or equal to 5.8, less than or equal to 6.4 and greater than or equal to 5.9, less than or equal to 6.4 and greater than or equal to 6.0, less than or equal to 6.4 and greater than or equal to 6.2, less than or equal to 6.3 and greater than or equal to 5.6, less than or equal to 6.3 and greater than or equal to 5.7, less than or equal to 6.3 and greater than or equal to 5.8, less than or equal to 6.3 and greater than or equal to 5.9, less than or equal to 6.3 and greater than or equal to 6.0, less than or equal to 6.3 and greater than or equal to 6.2, less than or equal to 6.2 and greater than or equal to 5.7, less than or equal to 6.2 and greater than or equal to 5.8, less than or equal to 6.2 and greater than or equal to 5.9, less than or equal to 6.2 and greater than or equal to 6.0, or even less than or equal to 6.2 and greater than or equal to 6.1, or any and all sub-ranges formed from any of these endpoints. As noted herein, while not wishing to be bound by theory, it is believed that the dielectric constant of the colored glass articles measured at 10 GHz approximates the dielectric constant at each frequency in the range from 10 GHz to 60 GHz. Accordingly, a dielectric constant reported for a colored glass article at a frequency of 10 GHz approximates the dielectric constant of the colored glass article at each frequency over the frequency range of 10 GHz to 60 GHz, inclusive of endpoints. 
     In embodiments, when the glass composition and the resultant colored glass articles satisfies the relationship 3.802946+0.01747*B 2 O 3 +0.058769*Al 2 O 3 +0.080876*Li 2 O+0.148433*Na 2 O+0.153264*K 2 O+0.045179*MgO+0.080113*CaO is less than or equal to 6.8, the dielectric electric constant Dk may be in the desired range (e.g., less than or equal to 6.8). For example, in embodiments, the glass composition and the resultant colored glass articles may satisfy the relationship 3.802946+0.01747*B 2 O 3 +0.058769*Al 2 O 3 +0.080876*Li 2 O+0.148433*Na 2 O+0.153264*K 2 O+0.045179*MgO+0.080113*CaO is less than or equal to 6.8 and greater than or equal to 5.7, less than or equal to 6.8 and greater than or equal to 5.8, less than or equal to 6.8 and greater than or equal to 5.9, less than or equal to 6.8 and greater than or equal to 6.0, less than or equal to 6.8 and greater than or equal to 6.2, less than or equal to 6.6 and greater than or equal to 5.7, less than or equal to 6.6 and greater than or equal to 5.8, less than or equal to 6.6 and greater than or equal to 5.9, less than or equal to 6.6 and greater than or equal to 6.0, less than or equal to 6.6 and greater than or equal to 6.2, less than or equal to 6.4 and greater than or equal to 5.7, less than or equal to 6.4 and greater than or equal to 5.8, less than or equal to 6.4 and greater than or equal to 5.9, less than or equal to 6.4 and greater than or equal to 6.0, less than or equal to 6.4 and greater than or equal to 6.2, less than or equal to 6.3 and greater than or equal to 5.6, less than or equal to 6.3 and greater than or equal to 5.7, less than or equal to 6.3 and greater than or equal to 5.8, less than or equal to 6.3 and greater than or equal to 5.9, less than or equal to 6.3 and greater than or equal to 6.0, less than or equal to 6.3 and greater than or equal to 6.2, less than or equal to 6.2 and greater than or equal to 5.7, less than or equal to 6.2 and greater than or equal to 5.8, less than or equal to 6.2 and greater than or equal to 5.9, less than or equal to 6.2 and greater than or equal to 6.0, or even less than or equal to 6.2 and greater than or equal to 6.1, or any and all sub-ranges formed from any of these endpoints. 
     The colored glass articles formed from the glass compositions described herein may be any suitable thickness, which may vary depending on the particular application of the colored glass article. In embodiments, the colored glass articles may have a thickness greater than or equal to 250 μm and less than or equal to 6 mm, greater than or equal to 250 μm and less than or equal to 4 mm, greater than or equal to 250 μm and less than or equal to 2 mm, greater than or equal to 250 μm and less than or equal to 1 mm, greater than or equal to 250 μm and less than or equal to 750 μm, greater than or equal to 250 μm and less than or equal to 500 μm, greater than or equal to 500 μm and less than or equal to 6 mm, greater than or equal to 500 μm and less than or equal to 4 mm, greater than or equal to 500 μm and less than or equal to 2 mm, greater than or equal to 500 μm and less than or equal to 1 mm, greater than or equal to 500 μm and less than or equal to 750 μm, greater than or equal to 750 μm and less than or equal to 6 mm, greater than or equal to 750 μm and less than or equal to 4 mm, greater than or equal to 750 μm and less than or equal to 2 mm, greater than or equal to 750 μm and less than or equal to 1 mm, greater than or equal to 1 mm and less than or equal to 6 mm, greater than or equal to 1 mm and less than or equal to 4 mm, greater than or equal to 1 mm and less than or equal to 2 mm, greater than or equal to 2 mm and less than or equal to 6 mm, greater than or equal to 2 mm and less than or equal to 4 mm, or even greater than or equal to 4 mm and less than or equal to 6 mm, or any and all sub-ranges formed from any of these endpoints. 
     As discussed hereinabove, colored glass articles formed from the glass compositions described herein may have an increased fracture toughness such that the colored glass articles are more resistant to damage. In embodiments, the colored glass article may have a K IC  fracture toughness as measured by a chevron notch short bar method greater than or equal to 0.7 MPa·m 1/2 , greater than or equal to 0.8 MPa·m 1/2 , greater than or equal to 0.9 MPa·m 1/2 , or even greater than or equal to 1.0 MPa·m 1/2 . 
     In embodiments, the glass compositions described herein are ion-exchangeable to facilitate strengthening the colored glass article made from the glass compositions. In typical ion-exchange processes, smaller metal ions in the glass compositions are replaced or “exchanged” with larger metal ions of the same valence within a layer that is close to the outer surface of the colored glass article made from the glass composition. The replacement of smaller ions with larger ions creates a compressive stress within the layer of the colored glass article made from the glass composition. In embodiments, the metal ions are monovalent metal ions (e.g., Li + , Na + , K + , and the like), and ion-exchange is accomplished by immersing the glass article made from the glass composition in a bath comprising at least one molten salt of the larger metal ion that is to replace the smaller metal ion in the colored glass article. Alternatively, other monovalent ions such as Ag ° , Tl + , Cu + , and the like may be exchanged for monovalent ions. The ion-exchange process or processes that are used to strengthen the colored glass article made from the glass composition may include contacting the colored glass article with an ion-exchange medium. In embodiments, the ion-exchange medium may be a molten salt bath. For example, the ion-exchange process may include, but is not limited to, immersion in a single bath or multiple baths of like or different compositions with optional washing and/or annealing steps between immersions. 
     Upon exposure to the colored glass article, the ion-exchange solution (e.g., KNO 3  and/or NaNO 3  molten salt bath) may, according to embodiments, be at a temperature greater than or equal to 350° C. and less than or equal to 500° C., greater than or equal to 360° C. and less than or equal to 450° C., greater than or equal to 370° C. and less than or equal to 440° C., greater than or equal to 360° C. and less than or equal to 420° C., greater than or equal to 370° C. and less than or equal to 400° C., greater than or equal to 375° C. and less than or equal to 475° C., greater than or equal to 400° C. and less than or equal to 500° C., greater than or equal to 410° C. and less than or equal to 490° C., greater than or equal to 420° C. and less than or equal to 480° C., greater than or equal to 430° C. and less than or equal to 470° C., or even greater than or equal to 440° C. and less than or equal to 460° C., or any and all sub-ranges between the foregoing values. In embodiments, the colored glass article may be exposed to the ion-exchange solution for a duration greater than or equal to 2 hours and less than or equal to 24 hours, greater than or equal to 2 hours and less than or equal to 12 hours, greater than or equal to 2 hours and less than or equal to 6 hours, greater than or equal to 8 hours and less than or equal to 24 hours, greater than or equal to 6 hours and less than or equal to 24 hours, greater than or equal to 6 hours and less than or equal to 12 hours, greater than or equal to 8 hours and less than or equal to 24 hours, or even greater than or equal to 8 hours and less than or equal to 12 hours, or any and all sub-ranges formed from any of these endpoints. 
     In embodiments, a colored glass article made from a glass composition may be ion-exchanged to achieve a depth of compression of 10 μm or greater, 20 μm or greater, 30 μm or greater, 40 μm or greater, 50 μm or greater, 60 μm or greater, 70 μm or greater, 80 μm or greater, 90 μm or greater, or 100 μm or greater. In embodiments, a colored glass article made from a glass composition may be ion-exchanged to achieve a depth of compression of 3 μm or greater or 5 μm or greater. In embodiments, the colored glass article made from the glass composition may have a thickness “t” and may be ion-exchanged to achieve a depth of compression greater than or equal to 0.15t, greater than or equal to 0.17t, or even greater than or equal to 0.2t. In embodiments, the colored glass article made from the glass composition may have a thickness “t” and may be ion-exchanged to achieve a depth of compression less than or equal to 0.3t, less than or equal to 0.27t, or even less than or equal to 0.25t. In embodiments, the colored glass article made from the glass composition described herein may have a thickness “t” and may be ion-exchanged to achieve a depth of compression greater than or equal to 0.15t and less than or equal to 0.3t, greater than or equal to 0.15t and less than or equal to 0.27t, greater than or equal to 0.15t and less than or equal to 0.25t, greater than or equal to 0.17t and less than or equal to 0.3t, greater than or equal to 0.17t and less than or equal to 0.27t, greater than or equal to 0.17t and less than or equal to 0.25t, greater than or equal to 0.2t and less than or equal to 0.3t, greater than or equal to 0.2t and less than or equal to 0.27t, or even greater than or equal to 0.2t and less than or equal to 0.25t, or any and all sub-ranges formed from any of these endpoints. 
     The development of this surface compression layer is beneficial for achieving a better crack resistance and higher flexural strength compared to non-ion-exchanged materials. The surface compression layer has a higher concentration of the ions exchanged into the colored glass article in comparison to the concentration of the ions exchanged into the colored glass article for the body (i.e., the area not including the surface compression) of the colored glass article. In embodiments, the colored glass article made from the glass composition may have a surface compressive stress after ion-exchange strengthening greater than or equal to 300 MPa, greater than or equal to 400 MPa, greater than or equal to 500 MPa, or even greater than or equal to 600 MPa. In embodiments, the colored glass article made from the glass composition may have a surface compressive stress after ion-exchange strengthening less than or equal to 1 GPa, less than or equal to 900 MPa, or even less than or equal to 800 MPa. In embodiments, the colored glass article made from the glass composition may have a surface compressive stress after ion-exchange strengthening greater than or equal to 300 MPa and less than or equal to 1 GPa, greater than or equal to 300 MPa and less than or equal to 900 MPa, greater than or equal to 300 MPa and less than or equal to 800 MPa, greater than or equal to 400 MPa and less than or equal to 1 GPa, greater than or equal to 400 MPa and less than or equal to 900 MPa, greater than or equal to 400 MPa and less than or equal to 800 MPa, greater than or equal to 500 MPa and less than or equal to 1 GPa, greater than or equal to 500 MPa and less than or equal to 900 MPa, greater than or equal to 500 MPa and less than or equal to 800 MPa, greater than or equal to 600 MPa and less than or equal to 1 GPa, greater than or equal to 600 MPa and less than or equal to 900 MPa, or even greater than or equal to 600 MPa and less than or equal to 800 MPa, or any and all sub-ranges formed from any of these endpoints. 
     In embodiments, the colored glass articles made from the glass composition may have a central tension after ion-exchange strengthening greater than or equal to 40 MPa, greater than or equal to 60 MPa, greater than or equal to 80 MPa, or even greater than or equal to 100 MPa. In embodiments, the colored glass article made from the glass composition may have a central tension after ion-exchange strengthening less than or equal to 250 MPa, less than or equal to 200 MPa, or even less than or equal to 150 MPa. In embodiments, the colored glass article made from the glass composition may have a central tension after ion-exchange strengthening greater than or equal to 40 MPa and less than or equal to 250 MPa, greater than or equal to 40 MPa and less than or equal to 200 MPa, greater than or equal to 40 MPa and less than or equal to 150 MPa, greater than or equal to 60 MPa and less than or equal to 250 MPa, greater than or equal to 60 MPa and less than or equal to 200 MPa, greater than or equal to 60 MPa and less than or equal to 150 MPa, greater than or equal to 80 MPa and less than or equal to 250 MPa, greater than or equal to 80 MPa and less than or equal to 200 MPa, greater than or equal to 80 MPa and less than or equal to 150 MPa, greater than or equal to 100 MPa and less than or equal to 250 MPa, greater than or equal to 100 MPa and less than or equal to 200 MPa, or even greater than or equal to 100 MPa and less than or equal to 150 MPa, or any and all sub-ranges formed from any of these endpoints. As utilized herein, central tension refers to a maximum central tension value unless otherwise indicated. 
     As described herein, the glass compositions described herein include a colorant that comprises or consists of transition metal oxides, rare earth oxides, or combinations thereof, to achieve a desired color. In embodiments, a colored glass article may have a transmittance color coordinate in the CIELAB color space, as measured at an article thickness of 1.33 mm under F2 illumination and a 10° standard observer angle, of L* greater than or equal to 65 and less than or equal to 98, a* greater than or equal to −20 and less than or equal to 10, and b* greater than or equal to −15 and less than or equal to 15. In embodiments, a colored glass article may have a transmittance color coordinate in the CIELAB color space, as measured under F2 illumination and a 10° standard observer angle, of L* greater than or equal to 65 and less than or equal to 98, a* greater than or equal to −20 and less than or equal to 10, and b* greater than or equal to −15 and less than or equal to 15. In embodiments, a colored glass article may have a transmittance color coordinate in the CIELAB color space, as measured at an article thickness of 1.33 mm under F2 illumination and a 10° standard observer angle, of L* greater than or equal to 65 and less than or equal to 98, absolute value of a* (i.e., |a*|) greater than or equal to 0.3; and absolute value of b* (i.e., |b*|) greater than or equal to 0.5. 
     The colored glass articles described herein may be used for a variety of applications including, for example, back cover applications in consumer or commercial electronic devices such as smartphones, tablet computers, personal computers, ultrabooks, televisions, and cameras. An exemplary article incorporating any of the colored glass articles disclosed herein is shown in  FIGS.  3  and  4   . Specifically,  FIGS.  3  and  4    show a consumer electronic device  100  including a housing  102  having front  104 , back  106 , and side surfaces  108 ; electrical components (not shown) that are at least partially inside or entirely within the housing and including at least a controller, a memory, and a display  110  at or adjacent to the front surface of the housing; and a cover substrate  112  at or over the front surface of the housing such that it is over the display. In embodiments, at least a portion of housing  102 , such as the back  106 , may include any of the colored glass articles disclosed herein. 
     EXAMPLES 
     In order that various embodiments be more readily understood, reference is made to the following examples, which illustrate various embodiments of the colored glass articles described herein. 
     Table 1 shows batch compositions utilized to form example colored glass articles 1-32 (in terms of mol %). 
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
             
            
               
                 Example 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 SiO 2   
                 61.74 
                 60.04 
                 61.06 
                 61.24 
                 61.20 
                 60.38 
               
               
                 Al 2 O 3   
                 15.04 
                 15.86 
                 15.39 
                 15.39 
                 15.42 
                 15.51 
               
               
                 B 2 O 3   
                 6.06 
                 6.19 
                 6.05 
                 5.95 
                 5.90 
                 5.93 
               
               
                 Li 2 O 
                 9.03 
                 8.93 
                 8.94 
                 9.93 
                 9.95 
                 8.65 
               
               
                 Na 2 O 
                 1.41 
                 1.40 
                 1.40 
                 1.50 
                 1.50 
                 1.41 
               
               
                 K 2 O 
                 0.20 
                 0.20 
                 0.20 
                 0.20 
                 0.20 
                 0.20 
               
               
                 CaO 
                 5.25 
                 6.12 
                 3.84 
                 1.32 
                 2.53 
                 3.83 
               
               
                 MgO 
                 0.99 
                 1.00 
                 2.88 
                 4.24 
                 3.08 
                 2.88 
               
               
                 ZnO 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 SnO 2   
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 Fe 2 O 3   
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 NiO 
                 0.0154 
                 0.0178 
                 0.0170 
                 0.0161 
                 0.0154 
                 — 
               
               
                 Co 3 O 4   
                 0.0001 
                 0.0001 
                 0.0001 
                 — 
                 — 
                 — 
               
               
                 Cr 2 O 3   
                 0.0297 
                 0.0287 
                 0.0272 
                 0.0280 
                 0.0266 
                 0.0008 
               
               
                 CuO 
                 0.2207 
                 0.1959 
                 0.1906 
                 0.1750 
                 0.1758 
                 0.0008 
               
               
                 CeO 2   
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.21 
               
               
                 TiO 2   
                 0.01 
                 0.01 
                 0.01 
                 0.01 
                 0.01 
                 0.99 
               
               
                 R 2 O 
                 10.64 
                 10.53 
                 10.54 
                 11.63 
                 11.65 
                 10.26 
               
               
                 R′O 
                 6.24 
                 7.12 
                 6.72 
                 5.56 
                 5.61 
                 6.71 
               
               
                 R 2 O + R′O 
                 16.88 
                 17.65 
                 17.26 
                 17.19 
                 17.26 
                 16.97 
               
               
                 NiO + Co 3 O 4  + 
                 0.266 
                 0.243 
                 0.235 
                 0.219 
                 0.218 
                 0.002 
               
               
                 Cr 2 O 3  + CuO 
               
               
                   
               
               
                 Example 
                 7 
                 8 
                 9 
                 10 
                 11 
                 12 
               
               
                   
               
               
                 SiO 2   
                 59.54 
                 61.59 
                 61.62 
                 61.34 
                 61.06 
                 61.24 
               
               
                 Al 2 O 3   
                 15.98 
                 15.28 
                 15.09 
                 15.32 
                 15.39 
                 15.39 
               
               
                 B 2 O 3   
                 5.90 
                 6.01 
                 5.94 
                 5.94 
                 6.05 
                 5.95 
               
               
                 Li 2 O 
                 8.69 
                 9.28 
                 9.30 
                 9.39 
                 8.94 
                 9.93 
               
               
                 Na 2 O 
                 1.52 
                 1.38 
                 1.47 
                 1.46 
                 1.40 
                 1.50 
               
               
                 K 2 O 
                 0.19 
                 0.20 
                 0.20 
                 0.20 
                 0.20 
                 0.20 
               
               
                 CaO 
                 1.88 
                 4.16 
                 4.19 
                 4.25 
                 3.84 
                 1.32 
               
               
                 MgO 
                 5.05 
                 1.89 
                 1.90 
                 1.93 
                 2.88 
                 4.24 
               
               
                 ZnO 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 SnO 2   
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 Fe 2 O 3   
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 NiO 
                 — 
                 0.0163 
                 — 
                 0.0234 
                 0.0170 
                 0.0161 
               
               
                 Co 3 O 4   
                 — 
                 — 
                 0.0023 
                 0.0094 
                 0.0001 
                 — 
               
               
                 Cr 2 O 3   
                 0.0008 
                 0.0256 
                 — 
                 — 
                 0.0272 
                 0.0280 
               
               
                 CuO 
                 — 
                 0.1638 
                 0.2810 
                 0.1165 
                 0.1906 
                 0.1750 
               
               
                 CeO 2   
                 0.21 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 TiO 2   
                 1.02 
                 0.01 
                 0.01 
                 0.01 
                 0.01 
                 0.01 
               
               
                 R 2 O 
                 10.40 
                 10.86 
                 10.97 
                 11.05 
                 10.54 
                 11.63 
               
               
                 R′O 
                 6.93 
                 6.05 
                 6.09 
                 6.18 
                 6.72 
                 5.56 
               
               
                 R 2 O + R′O 
                 17.33 
                 16.91 
                 17.06 
                 17.23 
                 17.26 
                 17.19 
               
               
                 NiO + Co 3 O 4  + 
                 0.001 
                 0.206 
                 0.283 
                 0.149 
                 0.235 
                 0.219 
               
               
                 Cr 2 O 3  + CuO 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Example 
                 13 
                 14 
                 15 
                 16 
                 17 
                 18 
               
               
                   
               
               
                 SiO 2   
                 61.14 
                 61.47 
                 61.13 
                 61.11 
                 61.32 
                 61.10 
               
               
                 Al 2 O 3   
                 15.41 
                 14.54 
                 14.65 
                 15.75 
                 15.29 
                 14.87 
               
               
                 B 2 O 3   
                 5.91 
                 5.92 
                 5.90 
                 5.79 
                 5.84 
                 5.95 
               
               
                 Li 2 O 
                 9.96 
                 9.92 
                 10.00 
                 9.24 
                 9.35 
                 9.96 
               
               
                 Na 2 O 
                 1.49 
                 1.83 
                 1.83 
                 1.36 
                 1.47 
                 1.86 
               
               
                 K 2 O 
                 0.20 
                 0.19 
                 0.19 
                 0.17 
                 0.20 
                 0.20 
               
               
                 CaO 
                 3.74 
                 1.99 
                 2.03 
                 4.31 
                 4.23 
                 2.06 
               
               
                 MgO 
                 1.92 
                 1.92 
                 1.94 
                 2.01 
                 1.99 
                 1.98 
               
               
                 ZnO 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 SnO 2   
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 Fe 2 O 3   
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 NiO 
                 0.0164 
                 — 
                 — 
                 0.0215 
                 — 
                 — 
               
               
                 Co 3 O 4   
                 — 
                 — 
                 — 
                 — 
                 0.0025 
                 — 
               
               
                 Cr 2 O 3   
                 0.0269 
                 — 
                 — 
                 0.0270 
                 — 
                 — 
               
               
                 CuO 
                 0.1693 
                 — 
                 — 
                 0.1761 
                 0.2642 
                 — 
               
               
                 CeO 2   
                 — 
                 0.20 
                 0.21 
                 — 
                 — 
                 0.42 
               
               
                 TiO 2   
                 0.01 
                 0.99 
                 0.99 
                 0.01 
                 0.05 
                 1.01 
               
               
                 R 2 O 
                 11.65 
                 11.94 
                 12.02 
                 10.77 
                 11.02 
                 12.02 
               
               
                 R′O 
                 5.66 
                 3.91 
                 3.97 
                 6.32 
                 6.22 
                 4.04 
               
               
                 R 2 O + R′O 
                 17.31 
                 15.85 
                 15.99 
                 17.09 
                 17.24 
                 16.06 
               
               
                 NiO + Co 3 O 4  + 
                 0.213 
                 — 
                 — 
                 0.225 
                 0.267 
                 — 
               
               
                 Cr 2 O 3  + CuO 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Example 
                 19 
                 20 
                 21 
                 22 
                 23 
                 24 
               
               
                   
               
               
                 SiO 2   
                 61.18 
                 61.42 
                 61.39 
                 61.04 
                 58.63 
                 59.17 
               
               
                 Al 2 O 3   
                 14.65 
                 14.92 
                 14.87 
                 14.73 
                 16.38 
                 16.61 
               
               
                 B 2 O 3   
                 6.14 
                 5.62 
                 5.78 
                 5.80 
                 6.05 
                 5.71 
               
               
                 Li 2 O 
                 10.05 
                 9.91 
                 9.85 
                 9.94 
                 9.95 
                 11.13 
               
               
                 Na 2 O 
                 1.86 
                 1.87 
                 1.86 
                 1.84 
                 4.28 
                 5.76 
               
               
                 K 2 O 
                 0.19 
                 0.20 
                 0.20 
                 0.19 
                 0.20 
                 0.19 
               
               
                 CaO 
                 2.02 
                 2.06 
                 2.06 
                 2.03 
                 — 
                 — 
               
               
                 MgO 
                 1.94 
                 1.99 
                 1.97 
                 1.95 
                 0.04 
                 0.02 
               
               
                 ZnO 
                 — 
                 — 
                 — 
                 — 
                 3.96 
                 0.99 
               
               
                 SnO 2   
                 — 
                 — 
                 — 
                 — 
                 0.01 
                 0.01 
               
               
                 Fe 2 O 3   
                 — 
                 — 
                 — 
                 — 
                 0.0044 
                 0.0040 
               
               
                 NiO 
                 — 
                 — 
                 — 
                 — 
                 — 
                 0.0138 
               
               
                 Co 3 O 4   
                 — 
                 — 
                 — 
                 — 
                 0.0027 
                 0.0024 
               
               
                 Cr 2 O 3   
                 — 
                 — 
                 — 
                 — 
                 0.0004 
                 0.0258 
               
               
                 CuO 
                 — 
                 — 
                 — 
                 — 
                 0.3340 
                 0.2233 
               
               
                 CeO 2   
                 0.41 
                 0.42 
                 0.42 
                 0.42 
                 — 
                 — 
               
               
                 TiO 2   
                 1.00 
                 1.02 
                 1.02 
                 1.01 
                 — 
                 — 
               
               
                 R 2 O 
                 12.10 
                 11.98 
                 11.91 
                 11.97 
                 14.42 
                 17.09 
               
               
                 R′O 
                 3.96 
                 4.05 
                 4.03 
                 3.98 
                 4.01 
                 1.02 
               
               
                 R 2 O + R′O 
                 16.06 
                 16.03 
                 15.94 
                 15.95 
                 18.43 
                 18.11 
               
               
                 NiO + Co 3 O 4  + 
                 — 
                 — 
                 — 
                 — 
                 0.337 
                 0.265 
               
               
                 Cr 2 O 3  + CuO 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Example 
                 25 
                 26 
                 27 
                 28 
                 29 
                 30 
               
               
                   
               
               
                 SiO 2   
                 58.78 
                 58.51 
                 58.74 
                 59.71 
                 60.28 
                 60.15 
               
               
                 Al 2 O 3   
                 16.52 
                 16.52 
                 16.30 
                 16.46 
                 16.48 
                 15.79 
               
               
                 B 2 O 3   
                 5.95 
                 6.06 
                 6.09 
                 5.95 
                 6.08 
                 6.14 
               
               
                 Li 2 O 
                 10.91 
                 10.50 
                 10.05 
                 10.45 
                 10.24 
                 8.95 
               
               
                 Na 2 O 
                 5.23 
                 4.77 
                 4.27 
                 4.78 
                 4.29 
                 1.41 
               
               
                 K 2 O 
                 0.19 
                 0.20 
                 0.19 
                 0.20 
                 0.20 
                 0.20 
               
               
                 CaO 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 MgO 
                 0.03 
                 0.04 
                 0.05 
                 0.03 
                 0.03 
                 1.98 
               
               
                 ZnO 
                 2.00 
                 3.01 
                 3.92 
                 1.99 
                 2.00 
                 5.01 
               
               
                 SnO 2   
                 0.01 
                 0.01 
                 0.01 
                 0.01 
                 0.01 
                 0.01 
               
               
                 Fe 2 O 3   
                 0.0044 
                 0.0044 
                 0.0044 
                 0.0040 
                 0.0044 
                 0.0052 
               
               
                 NiO 
                 0.0147 
                 0.0147 
                 0.0146 
                 0.0147 
                 0.0147 
                 0.0176 
               
               
                 Co 3 O 4   
                 0.0021 
                 0.0024 
                 0.0021 
                 0.0021 
                 0.0021 
                 0.0001 
               
               
                 Cr 2 O 3   
                 0.0267 
                 0.0267 
                 0.0262 
                 0.0263 
                 0.0268 
                 0.0291 
               
               
                 CuO 
                 0.1944 
                 0.2130 
                 0.2046 
                 0.2305 
                 0.2183 
                 0.1987 
               
               
                 CeO 2   
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 TiO 2   
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 R 2 O 
                 16.34 
                 15.46 
                 14.52 
                 15.43 
                 14.72 
                 10.55 
               
               
                 R′O 
                 2.03 
                 3.05 
                 3.97 
                 2.02 
                 2.03 
                 6.99 
               
               
                 R 2 O + R′O 
                 18.37 
                 18.51 
                 18.49 
                 17.45 
                 16.75 
                 17.55 
               
               
                 NiO + Co 3 O 4  + 
                 0.238 
                 0.257 
                 0.248 
                 0.274 
                 0.262 
                 0.245 
               
               
                 Cr 2 O 3  + CuO 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Example 
                 31 
                 32 
                 33 
                 34 
                 35 
               
               
                   
               
               
                 SiO 2   
                 59.03 
                 61.64 
                 60.95 
                 61.66 
                 60.89 
               
               
                 Al 2 O 3   
                 16.35 
                 15.05 
                 15.44 
                 15.11 
                 15.61 
               
               
                 B 2 O 3   
                 5.85 
                 5.87 
                 5.80 
                 5.94 
                 6.12 
               
               
                 Li 2 O 
                 11.86 
                 12.03 
                 9.78 
                 11.97 
                 9.49 
               
               
                 Na 2 O 
                 6.32 
                 3.93 
                 1.56 
                 3.94 
                 1.52 
               
               
                 K 2 O 
                 0.19 
                 0.39 
                 0.20 
                 0.39 
                 0.19 
               
               
                 CaO 
                 — 
                 — 
                 4.28 
                 0.76 
                 4.17 
               
               
                 MgO 
                 0.08 
                 0.02 
                 1.97 
                 0.03 
                 1.99 
               
               
                 ZnO 
                 — 
                 0.75 
                 — 
                 — 
                 — 
               
               
                 SnO 2   
                 — 
                 0.01 
                 — 
                 — 
                 — 
               
               
                 Fe 2 O 3   
                 0.0132 
                 0.0040 
                 0.0068 
                 0.0043 
                 0.0068 
               
               
                 NiO 
                 0.0112 
                 0.0116 
                 — 
                 0.0173 
                 — 
               
               
                 Co 3 O 4   
                 0.0027 
                 0.0118 
                 0.0017 
                 0.0025 
                 0.0010 
               
               
                 Cr 2 O 3   
                 0.0274 
                 −0.0240 
                 0.0034 
                 0.0277 
                 — 
               
               
                 CuO 
                 0.1659 
                 0.1673 
                 — 
                 0.14 
                 — 
               
               
                 CeO 2   
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 TiO 2   
                 — 
                 — 
                 0.01 
                 0.01 
                 0.01 
               
               
                 R 2 O 
                 18.37 
                 16.35 
                 11.54 
                 16.30 
                 11.20 
               
               
                 R′O 
                 0.08 
                 0.77 
                 6.25 
                 0.79 
                 6.16 
               
               
                 R 2 O + R′O 
                 18.44 
                 17.12 
                 17.79 
                 17.09 
                 17.36 
               
               
                 NiO + Co 3 O 4  + 
                 0.207 
                 0.205 
                 0.005 
                 0.185 
                 0.001 
               
               
                 Cr 2 O 3  + CuO 
               
               
                   
               
            
           
         
       
     
     Table 2 shows the dielectric constant (calculated) and dielectric constant (as measured at 10 GHz) for select examples from Table 1 at the indicated thickness. When calculated, the dielectric constant was calculated according to the following formula: 3.802946+0.01747*B 2 O 3 +0.058769*Al 2 O 3 +0.080876*Li 2 O+0.148433*Na 2 O+0.153264*K 2 O+0.045179*MgO+0.080113*CaO. Table 2 also shows the CIELAB coordinates for select samples from Table 1. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
             
            
               
                 Example 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 Dk (relationship 
                 6.23 
                 6.34 
                 6.21 
                 6.17 
                 6.21 
                 6.19 
               
               
                 calculated) 
               
               
                 Dk (measured 
                 6.13 
                 6.23 
                 6.18 
                 6.15 
                 6.19 
                 6.29 
               
               
                 at 10 GHz) 
               
               
                 L* 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 a* 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 b* 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 Thickness (mm) 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
               
               
                 Example 
                 7 
                 8 
                 9 
                 10 
                 11 
                 12 
               
               
                   
               
               
                 Dk (relationship 
                 6.18 
                 6.21 
                 6.22 
                 6.24 
                 6.21 
                 6.17 
               
               
                 calculated) 
               
               
                 Dk (measured 
                 6.21 
                 6.22 
                 — 
                 — 
                 — 
                 — 
               
               
                 at 10 GHz) 
               
               
                 L* 
                 — 
                 90.61 
                 92.48 
                 88.24 
                 90.14 
                 90.81 
               
               
                 a* 
                 — 
                 −8.02 
                 −4.39 
                 −1.61 
                 −8.48 
                 −7.43 
               
               
                 b* 
                 — 
                 4.61 
                 −3.85 
                 −4.42 
                 4.91 
                 4.98 
               
               
                 Thickness (mm) 
                 — 
                 1.32 
                 1.38 
                 1.36 
                 1.38 
                 1.34 
               
               
                   
               
               
                 Example 
                 13 
                 14 
                 15 
                 16 
                 17 
                 18 
               
               
                   
               
               
                 Dk (relationship 
                 6.26 
                 6.11 
                 6.13 
                 6.24 
                 6.24 
                 6.15 
               
               
                 calculated) 
               
               
                 Dk (measured 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 at 10 GHz) 
               
               
                 L* 
                 90.81 
                 96.68 
                 96.63 
                 89.23 
                 92.76 
                 96.11 
               
               
                 a* 
                 −7.6 
                 −0.4 
                 −0.39 
                 −7.87 
                 −4.26 
                 −1.36 
               
               
                 b* 
                 4.79 
                 1.28 
                 1.47 
                 3.88 
                 −3.53 
                 4.76 
               
               
                 Thickness (mm) 
                 1.34 
                 1.34 
                 1.34 
                 1.32 
                 1.37 
                 1.34 
               
               
                   
               
               
                 Example 
                 19 
                 20 
                 21 
                 22 
                 23 
                 24 
               
               
                   
               
               
                 Dk (relationship 
                 6.14 
                 6.14 
                 6.14 
                 6.13 
                 6.34 
                 6.67 
               
               
                 calculated) 
               
               
                 Dk (measured 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 at 10 GHz) 
               
               
                 L* 
                 96.11 
                 96.11 
                 96.11 
                 96.22 
                 — 
                 — 
               
               
                 a* 
                 −1.36 
                 −1.36 
                 −1.36 
                 −1.3 
                 — 
                 — 
               
               
                 b* 
                 4.76 
                 4.76 
                 4.76 
                 4.44 
                 — 
                 — 
               
               
                 Thickness (mm) 
                 1.34 
                 1.34 
                 1.34 
                 1.36 
                 — 
                 — 
               
               
                   
               
               
                 Example 
                 25 
                 26 
                 27 
                 28 
                 29 
                 30 
               
               
                   
               
               
                 Dk (relationship 
                 6.57 
                 6.47 
                 6.35 
                 6.46 
                 6.37 
                 5.89 
               
               
                 calculated) 
               
               
                 Dk (measured 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 at 10 GHz) 
               
               
                 L* 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 a* 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 b* 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 Thickness (mm) 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Example 
                 31 
                 32 
                 33 
                 34 
                 35 
               
               
                   
                   
               
               
                   
                 Dk (relationship 
                 6.80 
                 6.41 
                 5.95 
                 6.41 
                 5.94 
               
               
                   
                 calculated) 
               
               
                   
                 Dk (measured 
                 — 
                 — 
                 6.23 
                 6.41 
                 6.24 
               
               
                   
                 at 10 GHz) 
               
               
                   
                 L* 
                 — 
                 — 
               
               
                   
                 a* 
                 — 
                 — 
               
               
                   
                 b* 
                 — 
                 — 
               
               
                   
                 Thickness (mm) 
                 — 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     Table 3 shows the fracture toughness (K IC ) for select examples from Table 1 and a comparative example of a non-colored glass article comprising 58.5 mol % SiO 2 , 17.8 mol % Al 2 O 3 , 6.0 mol % B 2 O 3 , 10.7 mol % Li 2 O, 1.7 mol % Na 2 O, 0.2 mol % K 2 O, 4.5 mol % MgO, and 0.6 mol % CaO. The fracture toughness was measured using the chevron notch short bar (CNSB) method and the dual cantilever beam (DCB) method. 
     
       
         
           
               
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                   
                 K IC  CNSB 
                 K IC  DCB 
               
               
                 Example 
                 (MPa · m 1/2 ) 
                 (MPa · m 1/2 ) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 31 
                 0.774 
                 0.816 
               
               
                 8 
                 0.8 
                 0.839 
               
               
                 32 
                 0.794 
                 0.813 
               
               
                 Comparative example 
                 0.786 
                 0.877 
               
               
                   
               
            
           
         
       
     
     Table 4 shows the ion exchange characteristics (CS, DOC, and CT) for select colored glass articles from Table 1 at different thicknesses and ion exchange conditions (temperature, time, and ion exchange bath compositions). 
     
       
         
           
               
               
               
               
               
               
               
               
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                   
                 Thickness 
                 Temp 
                 Time 
                 KNO 3   
                 NaNO 3   
                 LiNO 3   
                 CS 
                 DOC 
                 CT 
               
               
                 Example 
                 (mm) 
                 (° C.) 
                 (hrs.) 
                 (wt %) 
                 (wt %) 
                 (wt %) 
                 (MPa) 
                 (μm) 
                 (MPa) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 23 
                 0.6 
                 440 
                 6.5 
                 79.2 
                 19.4 
                 1.4 
                 599 
                 5.62 
                 104.67 
               
               
                 24 
                 0.6 
                 430 
                 4 
                 79 
                 19.4 
                 1.6 
                 633 
                 6.02 
                 129.51 
               
               
                 25 
                 0.6 
                 430 
                 4 
                 79 
                 19.4 
                 1.6 
                 661 
                 5.03 
                 124.41 
               
               
                 26 
                 0.6 
                 430 
                 4 
                 79 
                 19.4 
                 1.6 
                 700 
                 3.83 
                 119.67 
               
               
                 27 
                 0.6 
                 430 
                 4 
                 79 
                 19.4 
                 1.6 
                 684 
                 3.97 
                 117.14 
               
               
                 27 
                 0.6 
                 430 
                 8 
                 79 
                 19.4 
                 1.6 
                 615 
                 4.79 
                 131.67 
               
               
                 27 
                 0.6 
                 430 
                 16 
                 79 
                 19.4 
                 1.6 
                 559 
                 6.82 
                 97.64 
               
               
                 27 
                 0.6 
                 440 
                 6 
                 79 
                 19.4 
                 1.6 
                 600 
                 5.29 
                 109.95 
               
               
                 27 
                 0.6 
                 440 
                 6 
                 79.2 
                 19.4 
                 1.4 
                 651 
                 4.67 
                 108.80 
               
               
                 27 
                 0.6 
                 440 
                 7 
                 79.2 
                 19.4 
                 1.4 
                 600 
                 5.40 
                 110.20 
               
               
                 27 
                 0.6 
                 440 
                 6.5 
                 79.2 
                 19.4 
                 1.4 
                 589 
                 5.56 
                 105.80 
               
               
                 28 
                 0.6 
                 430 
                 4 
                 79 
                 19.4 
                 1.6 
                 643 
                 5.56 
                 142.52 
               
               
                 29 
                 0.6 
                 430 
                 4 
                 79 
                 19.4 
                 1.6 
                 681 
                 5.24 
                 127.46 
               
               
                 30 
                 0.6 
                 450 
                 4 
                 90 
                 10 
                 0 
                 902 
                 3.52 
                 110 
               
               
                 30 
                 0.6 
                 450 
                 8 
                 90 
                 10 
                 0 
                 832 
                 4.52 
                 160 
               
               
                 30 
                 0.6 
                 450 
                 12 
                 90 
                 10 
                 0 
                 758 
                 5.62 
                 191 
               
               
                 30 
                 0.6 
                 450 
                 8 
                 89 
                 10 
                 1 
                 773 
                 3.54 
                 110 
               
               
                 30 
                 0.6 
                 450 
                 12 
                 89 
                 10 
                 1 
                 673 
                 4.65 
                 138 
               
               
                 30 
                 0.6 
                 450 
                 8 
                 88.5 
                 10 
                 1.5 
                 695 
                 3.64 
                 96 
               
               
                 30 
                 0.6 
                 450 
                 12 
                 88.5 
                 10 
                 1.5 
                 639 
                 4.17 
                 109 
               
               
                 13 
                 0.6 
                 450 
                 4 
                 90 
                 10 
                 0 
                 900 
                 3.99 
                 133 
               
               
                 13 
                 0.6 
                 450 
                 8 
                 90 
                 10 
                 0 
                 786 
                 5.61 
                 187 
               
               
                 13 
                 0.6 
                 450 
                 12 
                 90 
                 10 
                 0 
                 721 
                 7.55 
                 174 
               
               
                 13 
                 0.6 
                 450 
                 8 
                 89 
                 10 
                 1 
                 721 
                 4.89 
                 139 
               
               
                 13 
                 0.6 
                 450 
                 12 
                 89 
                 10 
                 1 
                 661 
                 5.76 
                 143 
               
               
                 13 
                 0.6 
                 450 
                 8 
                 88.5 
                 10 
                 1.5 
                 704 
                 4.39 
                 114 
               
               
                 13 
                 0.6 
                 450 
                 12 
                 88.5 
                 10 
                 1.5 
                 636 
                 5.69 
                 113 
               
               
                 31 
                 1.33 
                 400 
                 16 
                 89 
                 10 
                 1 
                 672 
                 9.1 
                 72 
               
               
                 31 
                 1.33 
                 400 
                 24 
                 89 
                 10 
                 1 
                 627 
                 11.2 
                 78 
               
               
                 31 
                 1.33 
                 430 
                 8 
                 80 
                 20 
                 0 
                 518 
                 11.6 
                 97 
               
               
                 31 
                 0.6 
                 380 
                 8 
                 79 
                 18.7 
                 2.3 
                 641 
                 4.1 
                 100 
               
               
                 31 
                 0.6 
                 380 
                 10 
                 79 
                 18.7 
                 2.3 
                 612 
                 4.7 
                 102 
               
               
                 31 
                 0.6 
                 380 
                 12 
                 79 
                 18.7 
                 2.3 
                 599 
                 5.2 
                 100 
               
               
                 31 
                 0.6 
                 410 
                 4 
                 79 
                 19.5 
                 1.5 
                 633 
                 5.3 
                 109 
               
               
                 31 
                 0.6 
                 410 
                 5 
                 79 
                 19.5 
                 1.5 
                 612 
                 5.9 
                 108 
               
               
                 31 
                 0.6 
                 410 
                 6 
                 79 
                 19.5 
                 1.5 
                 601 
                 6.1 
                 107 
               
               
                 31 
                 0.6 
                 400 
                 5 
                 79 
                 19.8 
                 1.2 
                 695 
                 5.0 
                 112 
               
               
                 31 
                 0.6 
                 400 
                 5 
                 79 
                 20.1 
                 0.9 
                 671 
                 5.3 
                 116 
               
               
                 31 
                 0.6 
                 400 
                 5 
                 79 
                 19.4 
                 1.6 
                 645 
                 5.0 
                 107 
               
               
                 31 
                 0.6 
                 430 
                 2.5 
                 79 
                 19.4 
                 1.6 
                 591 
                 6.0 
                 101 
               
               
                 31 
                 0.6 
                 430 
                 3 
                 79 
                 19.4 
                 1.6 
                 569 
                 6.1 
                 98 
               
               
                 31 
                 0.6 
                 430 
                 3.5 
                 79 
                 19.4 
                 1.6 
                 557 
                 6.8 
                 96 
               
               
                 31 
                 0.6 
                 430 
                 2.5 
                 75.6 
                 24 
                 0.4 
                 609 
                 6.41 
                 126 
               
               
                 31 
                 0.6 
                 430 
                 2.5 
                 76 
                 24 
                 0 
                 602 
                 7.57 
                 129 
               
               
                 31 
                 0.55 
                 400 
                 3 
                 79 
                 19.8 
                 1.2 
                 749 
                 3.69 
                 108 
               
               
                 8 
                 0.6 
                 450 
                 4 
                 89.8 
                 10 
                 0.2 
                 693 
                 5.54 
                 139 
               
               
                 8 
                 0.6 
                 450 
                 4 
                 89.8 
                 10 
                 0.2 
                 637 
                 7.54 
                 134 
               
               
                 8 
                 0.6 
                 450 
                 8 
                 89.5 
                 10 
                 0.5 
                 664 
                 5.56 
                 134 
               
               
                 8 
                 0.6 
                 450 
                 8 
                 88.5 
                 11 
                 0.5 
                 661 
                 5.59 
                 138 
               
               
                 8 
                 0.6 
                 450 
                 8 
                 87.5 
                 12 
                 0.5 
                 645 
                 5.69 
                 142 
               
               
                 8 
                 0.6 
                 450 
                 8 
                 86.5 
                 13 
                 0.5 
                 636 
                 5.74 
                 145 
               
               
                 8 
                 0.6 
                 450 
                 8 
                 89.5 
                 10 
                 0.5 
                 667 
                 5.52 
                 136 
               
               
                 8 
                 0.55 
                 450 
                 6.75 
                 87.3 
                 12.5 
                 0.2 
                 668 
                 5.64 
                 140 
               
               
                 8 
                 0.55 
                 450 
                 6.75 
                 87.5 
                 12.5 
                 0 
                 686 
                 5.63 
                 157 
               
               
                 8 
                 0.6 
                 440 
                 8 
                 88 
                 11 
                 1 
                 667 
                 4.32 
                 121 
               
               
                 8 
                 0.6 
                 440 
                 10 
                 88 
                 11 
                 1 
                 638 
                 5.10 
                 127 
               
               
                 8 
                 0.6 
                 440 
                 12 
                 88 
                 11 
                 1 
                 614 
                 5.64 
                 129 
               
               
                   
               
            
           
         
       
     
     Referring now to  FIGS.  5 - 8   , example colored glass article 8, having a thickness of 0.6 mm and strengthened in an ion-exchange bath of 89.3 wt % KNO 3 , 10 wt % NaNO 3 , and 0.7 wt % LiNO 3  at 400° C. for 9 hours, was subjected to Knoop Scratch Threshold testing with a load of 5N as shown in  FIGS.  5  and  6    and a load of 8N as shown in  FIGS.  7  and  8   . The Knoop Scratch Threshold testing was completed using a Bruker UMT (universal mechanical tester) with a knoop geometry diamond tip from Gilmore Diamonds. The tip was loaded into the material at a rate of 0.14 N/s to the desired load of 5N or 8N, at which point the tip was dragged laterally through the material at a rate of 9.34 mm/min. From there, the diamond tip was unloaded at a rate of 0.14 N/s. 
     Referring now to  FIG.  9   , the results of an incremental face drop on sandpaper (i.e., a “drop test”) for two different sandpaper conditions (180 grit and 80 grit) are shown for Examples 8 and 31 and a comparative example of a non-colored glass article comprising 58.5 mol % SiO 2 , 17.8 mol % Al 2 O 3 , 6.0 mol % B 2 O 3 , 10.7 mol % Li 2 O, 1.7 mol % Na 2 O, 0.2 mol % K 2 O, 4.5 mol % MgO, and 0.6 mol % CaO. Prior to performing the drop test, Example 31 was ion exchanged in a molten salt batch comprising 89.3 wt % KNO 3 , 10 wt % NaNO 3 , and 0.7 wt % LiNO 3  at 440° C. for 9 hours. Example 8 was ion exchanged in a molten salt batch comprising 79 wt % KNO 3 , 19.9 wt % NaNO 3 , and 1.6 wt % LiNO 3  at 400° C. for 5 hours. The comparative example was ion exchanged in a molten salt batch comprising 90.3 wt % KNO 3 , 9 wt % NaNO 3 , and 0.7 wt % LiNO 3  at 450° C. for 5 hours. 
     The circles in  FIG.  9    indicate at what height the sample fractured. The diamonds represent samples that were dropped incrementally all the way to 220 cm and did not fracture. As exemplified by  FIG.  9   , Examples 8 and 31, colored glass articles, exhibited similar drop performance as compared to a comparative example of a non-colored glass article. 
     Referring now to  FIG.  10   , the results of four point break testing after damage with sandpaper (i.e., a “slapper test”) for three different sandpaper conditions (1000 grit, 180 grit, and 80 grit) are shown for Example 8 and a comparative example of a non-colored glass article comprising 58.5 mol % SiO 2 , 17.8 mol % Al 2 O 3 , 6.0 mol % B 2 O 3 , 10.7 mol % Li 2 O, 1.7 mol % Na 2 O, 0.2 mol % K 2 O, 4.5 mol % MgO, and 0.6 mol % CaO. For the slapper test, samples of Example 8 and the comparative example were loaded onto a puck and slapped onto sandpaper having the identified grit using a particular force. The samples were not fractured, but were damaged after the sandpaper impact. The sample was then loaded into 4 point bending and the applied stress was incrementally increased until the sample broke. The applied stress at fracture is shown in  FIG.  10   . Prior to performing the slapper test, Example 8 was ion exchanged in a molten salt batch comprising 79 wt % KNO 3 , 19.9 wt % NaNO 3 , and 1.6 wt % LiNO 3  at 400° C. for 5 hours. The comparative example was ion exchanged in a molten salt batch comprising 90.3 wt % KNO 3 , 9 wt % NaNO 3 , and 0.7 wt % LiNO 3  at 450° C. for 5 hours. As exemplified by  FIG.  10   , Example 8, a colored glass article, exhibited similar slapper test results as compared to a comparative example of a non-colored glass article. 
     It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.