<PAGE>

                                                                  Exhibit 10.13


                         The United States of America

                  The Commissioner of Patents and Trademarks

Has received an application for a patent for a new and useful invention. The
title and description of the invention are enclosed. The requirements of law
have been complied with, and it has been determined that a patent on the
invention shall be granted under the law.

Therefore, this

                              United States Patent

Grants to the person(s) having title to this patent the right to exclude others
from making, using, offering for sale, or selling the invention throughout the
United States of America or importing the invention into the United States of
America for the term set forth below, subject to the payment of maintenance fees
as provided by law.

If this application was filed prior to June 8, 1995, the term of this patent is
the longer of seventeen years from the date of grant of this patent or twenty
years from the earliest effective U.S. filing date of the application, subject
to any statutory extension.

If this application was filed on or after June 8, 1995, the term of this patent
is twenty years from the U.S. filing date, subject to any statutory extension.
If the application contains a specific reference to an earlier filed application
or applications under 35 U.S.C. 120, 121 or 365(c), the term of the patent is
twenty years from the date on which the earliest application was filed, subject
to any statutory extension.

/s/ Bruce Lehman

Commissioner of Patents and Trademarks


/s/ Marjorie V. Turner

Attest

<PAGE>

                                    NOTICE

If the application for this patent was filed on or after December 12, 1980,
maintenance fees are due three years and six months, seven years and six months,
and eleven years and six months after the date of this grant, or within a grace
period of six months thereafter upon payment of a surcharge as provided by law.
The amount, number and timing of the maintenance fees required may be changed by
law or regulation. Unless payment of the applicable maintenance fee is received
in the Patent and Trademark Office on or before the date the fee is due or
within a grace period of six months thereafter, the patent will expire as of the
end of such grace period.

<PAGE>

United States Patent [19]                   [11] Patent Number:       5,671,735

MacFarlane et al.                          [45] Date of Patent:  Sep. 30, 1997
------------------------------------------------------------------------------
[54] METHOD AND APPARATUS FOR DETECTING AND MEASURING CONDITIONS AFFECTING COLOR

[75] Inventors: Darby Simpson MacFarlane; David
                Kenneth MacFarlane, both of
                Hastings-on-Hudson; Fred W.
                Billmeyer, Jr., Schenectady, all of N.Y.

[73] Assignee:  Chromatics Color Sciences
                International, Inc., New York, N.Y.

[21] Appl. No.: 239,733

[22] Filed:     May 9, 1994

                        Related U.S. Application Data

[63] Continuation-in-part of Ser. No. 21,657, Feb. 22, 1993, Pat. No. 5,313,267,
     which is a continuation of Ser. No. 818,488, Dec. 30, 1991, abandoned,
     which is a continuation of Ser. No. 402,815, Aug. 24, 1989, abandoned,
     which is a continuation-in-part of Ser. No. 306,286, Feb. 2, 1989,
     abandoned, which is a continuation of Ser. No. 204,938, Jun. 6, 1988,
     abandoned, which is a continuation of Ser. No. 904,369, Sep. 8, 1986,
     abandoned, which is a continuation-in-part of Ser. No. 833,661, Feb. 21, 
     1986, abandoned, which is a continuation of Ser. No. 514,618, Jul. 18, 
     1983, abandoned.
 

[51] Int. Cl(Superscript 6) ................ A61B 5/00
[52] U.S. Cl. .............................. 128/633; 128/665; 356/405
[58] Field of Search ....................... 128/630, 632, 128/633, 665; 356/405

[56]                          References Cited
                             US PATENT DOCUMENTS
    Re.  31,815    1/1985 Alfano ............. 128/665
        205,578    7/1878 Rose et al. .
      1,582,122    4/1926 Clapp .
      1,629,330    5/1927 Adler .
      1,741,080   12/1929 Stenz .

                        (List continued on next page.)

                           FOREIGN PATENT DOCUMENTS

                     655221  5/1995  European Pat. Off. .

                        (List continued on next page.)

                              OTHER PUBLICATIONS

M. Kenny et al. "Transcutaneous Bilirubin Monitoring of Newborns", Annals of 
the New York Academy of Sciences, vol. 428, pp. 251-262 (1984).

                        (List continued on next page.)

Primary Examiner--Jennifer Bahr
Assistant Examiner--Eric F. Winakur
Attorney, Agent, or Firm--Brumbaugh, Graves, Donohue & Raymond

[57]                       ABSTRACT

        
A method and apparatus for determining the condition of a test subject based on
color uses a color measuring instrument to detect change in a color factor
indicative of a condition such as a disease, spoilage, ageing, etc. A medical
condition such as hyperbilirubinemia that affects skin color can be detected.
One measures color factors such as Hunter b and L in the subjects' skin color.
For predetermined ranges of one color factor, in particular L, changes in the
other color factor, e.g. Hunter b, above predetermined levels are indicative of
the medical condition. In many cases, a single measurement of the color factors
can be utilized as a warning of the likelihood of the medical or contaminated
condition, if the ordinary range of the color factor is known for healthy
individuals with skin coloration like that of the test subject. Even if there
has been no baseline measurement and the test subject's color is such that a
single reading of one or two color factors will not warn of the possible
presence of the medical condition or contamination, sequential readings can
indicate the presence or absence of the condition based upon changes in the
measured color factor, or lack of changes. The color measuring techniques apply
to a wide range of biological test subjects (e.g. hair, teeth, tissue,
excretions, foods, soil, animals, plants).

                         74 Claims, 3 Drawing Sheets

   ----------------                           --------------------    
  |1. AT TIME t(0) |      -------------      | 3. DISCARD HIGHEST |  
  |    MULTIPLE    |     | 2.CALCULATE |     |  AND LOWEST HUNTER |  
  |  COLORIMETER   |     |   HUNTER    |-\   |  b AND ASSOCIATED  |-\____
  | MEASUREMENTS   |-\   | L & b FOR   |-/   |  VALUES OF L       |-/    |
  | OF Y, x & y    |-/   | EACH READING|     | FROM EACH SITE AND |      |
  | FROM EACH      |     |_____________|     | AVERAGE REMAINING  |      |
  | OF SEVERAL     |                         |       VALUES       |      |
  |  SITES         |                          --------------------       |
   ----------------                                                      |
                                                                         |
   ----------------------------------------------------------------------
  |
  |                                                                  
  |                                  -------------------
  |                                 | 5. REPEAT         |
  |                                 | STEPS 1-4         |
  |_ -\         -------------       |  AT TIMES         |-\____
     -/        | 4. RECORD   |-\    |t(1), t(2)...      |-/    |
               |  L(0) & b(0)|-/    | TO ARRIVE         |      |
                -------------       |AT L(1) & b(1),    |      |
                                    | L(2) & b(2)...    |      |
                                     -------------------       |  
                                                               |
   ------------------------------------------------------------
  |
  |                                                        -------------------
  |                                                       |  9. DETERMINE     |
  |    -------------------                                |      WHETHER      |
  |   | 6. COMPARE        |     --------------------      |b(1), b(2)..)-b(0) |
  |-\ | L(0) &L(1), L(2)  |-\  | 8. CALCULATE       |-\   |    IS ABOVE       |
   -/ |     FOR           |-/  |(b(1), b(2)...)-b(0)|-/   |  BILIRUBINEMIA    |
      | CONSISTENCY       |     --------------------      |  THRESHOLD FOR    |
       -------------------                                |  VALUE OF L       |
            | |                                            -------------------  
            \ /                                 
       ---------------------- |   
      | 7. DISCONTINUE        |
      | IF L(0) &L(1), L(2)...|
      |  INCONSISTENT         |   
       ---------------------- |           


<PAGE>

                                  5,671,735
                                    Page 2
______________________________________________________________________________

                            U.S. PATENT DOCUMENTS
1,979,119  10/1934  Radzinsky............................................36/17
2,221,774  11/1940  Bowser
3,003,388  10/1961  Hunter et al. .....................................356/405
3,533,399  10/1970  Goldberg et al.
3,736,064   5/1973  Kent et al. .......................................356/195
4,029,085   6/1977  DeWitt et al. .....................................128/633
4,093,991   6/1978  Christie, Jr. et al. ..............................364/525
4,135,497   1/1979  Meyers et al. .....................................128/2 H
4,241,738  12/1980  Lubbers et al. ....................................128/666
4,267,844   5/1981  Yamanishi..........................................128/633
4,302,971  12/1981  Luk.................................................73/356
4,357,106  11/1982  Tschirren et al. ...................................356/44
4,423,736   1/1984  DeWitt et al. .....................................128/633
4,479,499  10/1984  Alfano et al. .....................................128/665
4,561,850  12/1985  Fabbri et al. .....................................434/100
4,654,794   3/1987  O'Brien ...........................................364/413
4,681,546   7/1987  Hart ...............................................434/99
4,723,554   2/1988  Oman et al. .......................................128/664
4,842,523   6/1989  Bourdier et al. ...................................434/371
4,857,071   8/1989  Anderson ............................................8/414
4,877,034  10/1989  Atkins et al. .....................................128/664
4,894,547   1/1990  Leffell et al. ..................................250/461.2
4,909,632   3/1990  Macfarlane ........................................356/402
4,964,874  10/1990  Saphakkul ...........................................8/429
5,127,406   7/1992  Yamaguchi .........................................128/633
5,161,553  11/1992  Cohen et al. ......................................132/205
5,259,382  11/1993  Kronberg ..........................................128/633
5,311,293   5/1994  Macfarlane et al. .................................356/421
5,313,267   5/1994  MacFarlane et al. .................................356/405
5,337,745   8/1994  Benaron et al. ....................................128/633
5,344,463   9/1994  Chan et al. .........................................8/408
5,353,790  10/1994  Jacques et al. ....................................128/633
5,387,977   2/1995  Berg et al. .......................................356/407

                           FOREIGN PATENT DOCUMENTS

  1347400  11/1963  France
  1468339  12/1966  France
  2587181   3/1987  France
  1236984   3/1967  Germany
  3827457   6/1989  Germany
  0037896   8/1985  Japan
  0257328  12/1985  Japan
  8401665  12/1985  Netherlands
  2001595  10/1993  U.S.S.R.

                              OTHER PUBLICATIONS

R.E. Hannemann et al., "Neonatal Serum Bilirubin from Skin Reflectance",
Pediatric Research, vol. 12, pp. 207-210 (1978).

F. Billmeyer, Jr., "Quantifying Color Appearance Visually and Instrumentally",
Color Research and Applications, vol. 13, pp. 140-145 (1988).

T. Hegyi, M.D., "Transcutaneous Bilirubinometry In The Newborn Infant: State of
the Art", Journal of Clinical Monitoring, vol. 2, pp. 53-59 (1986).

R.E. Hanneman et al., "Evaluation of Minolta Bilirubin Meter as a Screening
Device", Pediatrics, vol. 69, pp. 107-109 (1982).

D. Onks et al., "Effect of Melanin, Oxyhemoglobin and Bilirubin on
Transcutaneous Bilirubinometry", Acta. Peadiatica, vol. 82, pp. 19-21 (1993).

F.D. Ortega et al., "Bilirrubinometria Transcutanea: Correlacion del Area de
Medida Con La Espectropometria y Colorimetria Por Diazorreaccion", Am. Exp.
Pediarr., vol. 39, pp. 438-440 (1993).

R.E. Schumacher, "Noninvasive Measurement of Bilirubin in the Newborn", clinics
in Perinatology, vol. 17, pp. 417-435 (1990).

I. Yamanouchi et al., "Transcutaneous Bilirubinometry: Preliminary Studies of
Noninvasive Transcutaneous Bilirubin Meters in the Okayama National Hospital",
Pediatrics, vol. 65, pp. 195-202 (1980).

Advertisement for portable photometer by Photo Research in Optica Spectra, Nov.,
1973.

D. Tudehope et al., "Non-invasive method of measuring bilirubin levels in
newborn infants", Medical Journal of Australia, vol. 1, pp. 165-168 (1982).

C. Jackson, Color Me Beautiful, New York Ballantine Books, Apr. 1981, pp. 25,
26, Color Palettes, 37-39, 41-59, 61-74, 143-147.

G. Pickney et al., Your New Image Through Color & Line, California Fashion
Image/Crown Summit Books, Sep. 1981, pp. 1-3, 17, 21-29, 97-105, 111, 112,
120-127.

R. Evans, An Introduction To Color, Wiley, New York, 1948, pp. 26-27 and 87-90.

C.S. McCamy et al., A Color-Rendition Chart, J. Appl. Photogr. Eng. vol. 2, 
pp. 95-99 (1976).

C.A. Pearson, Face Colour As A Sign Of Tuberculosis, Color Res. Appl. vol. 7,
pp. 31-33, (1982).

P.A. Lovett et al., Measurement of the Skin Color of Babies in Hospital, Proc.
of CIBS Lighting Conference, 1986, HMSO, London, 1986, pp. 140-154.

G. Wyszecki et al., Color Science, 2nd Edition (1982) Table of Contents, pp.
63-72.

F. Billmeyer & M. Saltzman, "Principles of Color Technology," 2nd ed., John
Wiley & Sons, New York, N.Y. 1981 pp. 18-19, 59-61, 92.

<PAGE>

U.S. Patent           Sep. 30, 1997           Sheet 1 of 3            5,671,735

                                                  -----------
                                                 / - - - - /
 11     -------------10     ---------15     ----/ - - - - /
|    12 |           |       |       |       |  -----------
|{------|           | Y,x,y |       |       | OUTPUT |
|       |COLORIMETER|------}|  CPU  |------}| DEVICE |
|------}|           |       |       |       |        |
|  13   |           |       |       |       ----------
        -------------       ---------
                                ^
                                |
                       --------------------17
                       |        |         |

                       |  ROM   |   RAM   |

                       |        |(FIG. 1a)|
                       -------------------- 
                              MEMORY
       FIG. 1








            RANGES OF L              |
                                     |
           TABLE II DATA             |
                                     |             
                                      } 18a
                                     |
           TABLE III DATA            |
                                     |
  (delta)L INDICATIVE OF ERROR       |
                                     |
(delta)b INDICATIVE OF CONDITION     |
                                     |
   (delta)b WARNING LEVEL            |
                                     |                FIG. 1a
=====================================
                                     |                                 
         CALIBRATION VALUES          |
                                     |
           BASELINE VALUES           |
                                     |
       PREVIOUS (AVG.) HUNTER        |
               L,a&b                 |
                                     |
                                     |  
                                     |
         CURRENT MULTIPLE             }   18b
       MULTISITE (UNAVERAGED)        |
           HUNTER  L,a&b             |
                                     |  
        CURRENT (AVG.) HUNTER        |
               L,a&b                 |                
   
<PAGE>

U.S. Patent         Sep. 30, 1997      Sheet 2 of 3         5,671,735


   ----------------                           --------------------    
  |1. AT TIME t(0) |      -------------      | 3. DISCARD HIGHEST |  
  |    MULTIPLE    |     | 2.CALCULATE |     |  AND LOWEST HUNTER |  
  |  COLORIMETER   |     |   HUNTER    |-\   |  b AND ASSOCIATED  |-\____
  | MEASUREMENTS   |-\   |L  & b FOR   |-/   |  VALUES OF L       |-/    |
  | OF Y, x & y    |-/   | EACH READING|     | FROM EACH SITE AND |      |
  | FROM EACH      |     |_____________|     | AVERAGE REMAINING  |      |
  | OF SEVERAL     |                         |       VALUES       |      |
  |  SITES         |                          --------------------       |
   ----------------                                                      |
                                                                         |
   ----------------------------------------------------------------------
  |
  |                                                                  
  |                                  -------------------
  |                                 | 5. REPEAT         |
  |             -------------       | STEPS 1-4         |
  |_ -\        | 4. RECORD   |-\    |  AT TIMES         |-\____
     -/        |  L(0) & b(0)|-/    |t(1), t(2)...      |-/    |
                -------------       | TO ARRIVE         |      |
                                    |AT L(1) & b(1),    |      |
                                    | L(2) & b(2)...    |      |
                                     -------------------       |  
                                                               |
   ------------------------------------------------------------
  |
  |                                                        --------------------
  |                                                       |  9. DETERMINE      |
  |    -------------------                                |      WHETHER       |
  |   | 6. COMPARE        |     --------------------      |(b(1), b(2)...)-b(0)|
  |-\ | L(0)&L(1), L(2)...|-\  | 8. CALCULATE       |-\   |     IS ABOVE       |
   -/ |     FOR           |-/  |(b(1), b(2)...)-b(0)|-/   |   BILIRUBINEMIA    |
      | CONSISTENCY       |     --------------------      |   THRESHOLD FOR    |
       -------------------                                |   VALUE OF L       |
            | |                                            -------------------- 
            \ /                                 
      -----------------------    
     | 7. DISCONTINUE        |
     |  IF L(0)&L(1), L(2)...|              FIG. 2
     |  INCONSISTENT         |   
      -----------------------            

<PAGE>

U.S. Patent         Sep. 30, 1997      Sheet 3 of 3         5,671,735




   ----------------                           --------------------    
  |1. AT TIME t(0) |      -------------      | 3. DISCARD HIGHEST |  
  |    MULTIPLE    |     | 2.CALCULATE |     |  AND LOWEST HUNTER |  
  |  COLORIMETER   |     |   HUNTER    |-\   |  b AND ASSOCIATED  |-\____
  | MEASUREMENTS   |-\   |L, a & b FOR |-/   |  VALUES OF L AND a |-/    |
  | OF Y, x & y    |-/   | EACH READING|     | FROM EACH SITE AND |      |
  | FROM EACH      |     |_____________|     | AVERAGE REMAINING  |      |
  | OF SEVERAL     |                         |       VALUES       |      |
  |  SITES         |                          --------------------       |
   ----------------                                                      |
                                                                         |
   ----------------------------------------------------------------------
  |
  |                                                                  
  |      --------------                            -------------------
  |     | 4. COMPARE a |                          | 7. REPEAT         |
  |     | WITH RANGE   |                          | STEPS 1-5         |
  |_ -\ |  OF a's      |      -------------       |  AT TIMES         |-\____
     -/ | PREVIOUSLY   | -\  | 6. RECORD   |-\    |t(1), t(2)...      |-/    |
        | ENCOUNTERED  | -/  |  L(0) & b(0)|-/    | TO ARRIVE         |      |
        |FOR CALCULATED|      -------------       |AT L(1), a(1)&b(1),|      |
        |  L & b       |                          | L(2),a(2)&b(2)... |      |
         --------------                            -------------------       |  
              | |                                                            |
FIG. 3        | |                                                            |
              | |                                                            |
              \ /                                                            |
      --------------------                                                   |
     | 5. DISCONTINUE     |                                                  |
     |    IF a's ARE      |                                                  |
     |   INCONSISTENT     |                                                  |
      --------------------                                                   |
                                                                             |
   --------------------------------------------------------------------------
  |
  |                                                        --------------------
  |                                                       | 11. DETERMINE      |
  |    -------------------                                |      WHETHER       |
  |   | 8. COMPARE        |     --------------------      |(b(1), b(2)...)-b(0)|
  |-\ | L(0) &L(1), L(2)  |-\  |10. CALCULATE       |-\   |    IS ABOVE        |
   -/ |     FOR           |-/  |(b(1), b(2)...)-b(0)|-/   |  BILIRUBINEMIA     |
      | CONSISTENCY       |     --------------------      |  THRESHOLD FOR     |
       -------------------                                |  VALUE OF L        |
            | |                                            -------------------- 
            \ /                                 
       ----------------------    
      |9. DISCONTINUE        |
      |IF L(0) &L(1), L(2)...|
      | INCONSISTENT         |   
       ----------------------            
<PAGE>

                              5,671,735

                                      1

METHOD AND APPARATUS FOR 
DETECTING AND MEASURING 
CONDITIONS AFFECTING COLOR

SPECIFICATION

This is a continuation-in-part of U.S. patent application Ser. No. 08/021.657,
filed Feb. 22, 1993, now U.S. Pat. No. 5,313,267, incorporated herein by
reference. Ser. No. 08/021,657 is a continuation of Ser. No. 818,488, filed Dec.
30, 1991, now abandoned, a continuation of Ser. No. 402,815, filed Aug. 24,
1989, now abandoned, a continuation-in-part of Ser. No. 306,286, filed Feb. 2,
1989, now abandoned, a continuation of Ser. No. 204,938, filed Jun. 6, 1988, now
abandoned, a continuation of Ser. No. 904,369, filed Sep. 8, 1986, now
abandoned, a continuation-in-part of U.S. patent application Ser. No. 833,661,
filed Feb. 21, 1986, now abandoned, which is a continuation of U.S. patent
application Ser. No. 514,618, filed Jul. 18, 1983, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to a method and apparatus for the detection and/or
measurement of a condition that affects the color of a test subject, and more
particularly to a process and instrument for measuring at least one color
characteristic or factor of a biological test subject indicative of the
condition of interest.

Visual observation of a subject for changes in coloration indicative of a
particular condition has often occurred. The subject may be a person or animal
being observed to determine the presence or absence of a medical condition. The
color characteristics or a single color characteristic of other test subjects
such as biopsy specimens or excretions have diagnostic value.

An individual person's skin color is often assessed by her or his doctor.
Hypertension, tuberculosis, sclerosis of the liver, to name just a few, are
examples of ailments with symptomatic skin color changes among at least a
sizeable population segment. Hair color evaluation and dental coloration
evaluation are valuable. These may bear on the health of the individual, or
on the health of the individual's hair and teeth, or these may permit accurate
cosmetic activities, for example, to counteract graying or to accurately match
new dental work to existing teeth.

Likewise, the condition of plants and agricultural products is visually
inspected for color as an indication of condition. Contamination of soil is
likewise apparent from visual inspection. Such visual inspections are
subjective. Measuring by instrument the color characteristics that are key to 
the visual inspection has the benefit of objectivity and consistency.

In the past, hyperbilirubinemia in newborns has been directed by visually
observing an individual for jaundice or by routinely taking and testing a blood
sample. Upon detection, hyperbilirubinemia has been treated by phototherapy.
During the course of phototherapy, blood samples have been taken and tested at
regular intervals until it was determined that the level of serum bilirubin had
decreased to an acceptable level.

In infants, there is little blood available for use in the blood testing for
hyperbilirubinemia. So much blood is drawn that transfusions are often necessary
to replace the drawn blood. The newborn is thereby exposed to all of the risks 
that transfusions bring. Blood sampling and transfusions are, of course, painful
to the newborn, and as with any

<PAGE>
                                      2

invasive procedure, both present medical risks, such as for example, risk of
infection. There is a need, therefore, for a reliable, noninvasive technique for
detecting and measuring a skin color affecting medical condition such as
hyperbilirubinemia.

This is one example of a wider need for procedures and instruments to 
objectively and consistently determine a color characteristic or factor 
indicative of the condition of a test suject or indicative of a particular 
ailment or condition.  The methods and apparatus of this invention can be 
employed where previously visual inspection, of which examples are given above,
have been carried out at least in part on the basis of observable color 
characteristics.

                    BRIEF SUMMARY OF THE INVENTION
  
According to this invention there is provided a method and apparatus for
detecting and quantitatively measuring a condition affecting the color
of a test subject. The method includes measuring at least one color
characteristic of the subject.

In one exemplary procedure according to this invention at least one skin
color characteristic is measured at least at first and second points in
time and compared for change to test for hyperbilirubinemia. In the
preferred procedure a second skin color characteristic is also measured 
on the basis of which the subject can be assigned to one of plural
categories among which varying amounts of change in the first-mentioned
skin color characteristic are indicative of the presence of a medical
condition. The first characteristic is then observed for a change of
measured value sufficient to indicate the medical condition for a
subject in that category. Preferably, a base reading of at least the
first color characteristic is first made at a time the subject is
without characteristic skin color change indicative of the medical
condition for which he or she is to be tested.

In the case of hyperbilirubinemia detection, the first skin color
characteristic is Hunter b, which is a color factor dependent on the
relative content, in a color, of two opponent colors, yellow and blue,
Hunter b is a factor comprising a first function (Y) weighted in a first
portion of the spectrum, the yellower portion, a second function (Z)
weighted in a second portion of the spectrum, the bluer portion, and a weighting
term (1/Y(to the 1/2 power)) that is a function of the lightness of a color and
that decreases the value of the color factor as lightness increases. Y and Z are
part of the three tristimulus values X, Y and Z known to the color scientist for
the purpose of defining a color. They are measurable by commercially available
instruments such as colorimeters.

In case of testing newborns for hyperbilirubinemia, readings of Hunter b
and the Hunter lightness measure L are made shortly after birth. These
can provide the base reading since hyperbilirubinemia does not manifest
itself immediately after birth. The first reading is made typically
within preferably five hours, but as soon as possible after birth.
Subsequent readings, are then made during the next few days. The
subsequent readings of Hunter b are compared with the first, baseline
reading of Hunter b to determine whether Hunter b has increased to an
extent that indicates a degree of jaundice characteristic of
hyperbilirubinemia for a person having the subject's particular skin
lightness L. L is measured during each subsequent test to be sure that
it remains close to the original reading. This gives a degree of
confidence that the test procedures are being conducted appropriately.

In the event that the medical condition affecting skin color is detected
in a procedure like that described above for
 
<PAGE>
                                  5,671.735

                                      3

hyperbilirubinemia, then the measuring of skin color characteristics  continues
at regular intervals until the symptomatic color characteristic abates
sufficiently to indicate the individual's recovery from the medical condition.
In the case of hyperbilirubinemia, phototherapy is administered once a
sufficient change in Hunter b is observed to indicate the jaundice of
hyperbilirubinemia. Throughout the course of phototherapy, then, the Hunter b
and L characteristics are continually monitored until the jaundice has been
eliminated. This is valuable in removing the newborn from under the phototherapy
lamps, since there is the danger of damage to the newborn's eyes in the event
eye protection is prematurely removed or accidentally dislodged.

The apparatus used in accordance with this invention includes a color measuring
device such as a colorimeter and computational means for storing and comparing
the characteristic or characteristics that are measured when testing for the
medical condition. Where Hunter b is measured for the purpose of detecting
hyperbilirubinemia, a colorimeter capable of calculating Hunter b and L can be
used. This can be a commercially available colorimeter with this capability. The
computational means preferably has sufficient memory to store one or more
previous readings and should be programmed to compare previous and current 
readings to detect changes in Hunter b and L. Preferably the colorimeter
and the computational means are integrated in a single instrument, but the
commercial colorimeter can be utilized in cooperation with, for example, a
personal computer, which stores and can compare Hunter b and L values from
measurements taken at timed intervals. Likewise, the computational means, 
whether an integrated part of the instrument or a separate computer, can be used
to store ranges of lightness L and the increases in Hunter b that, for the
various lightness ranges, indicate an unacceptable increase in serum bilirubin.

  Preferably, each skin color characteristic measurement used to assess the
presence or absence of the condition for which testing is carried out is
actually an average of multiple tests. For example, when newborns are tested for
the jaundice that signals hyperbilirubinemia, multiple readings are made at
multiple sites. Five or six of the readings from which Hunter b and L (and
perhaps a third characteristic, Hunter a, as described below) are made at,
for example, each of several locations which may include some or all of two
forehead locations, at least one chest location, a cheek location and two back
locations. At each site, the Hunter readings that have the highest and lowest
values of b are discarded, then all of the readings of each Hunter
characteristic are averaged. Subsequent readings are made in the same manner and
compared. As used herein, the terms "Hunter a", "Hunter b" and "Hunter L"
include such average values, but are not limited to just the values arrived at
by the averaging technique unless expressly so-limited. The discarding and
averaging is readily accomplished by the computational provisions of the test
equipment. The averaging technique may improve the testing of other than skin
color where the testing steps of this invention are used, for example in the
evaluation of hair by color measurement.

  In skin color testing, it is important to cleanse the site uitilizing a
cleansing agent that does not contribute any coloration. Likewise, when testing
is carried out on test subjects other than an individual's skin, the test
subject should be free of any color altering contaminant. In skin color testing,
the site on the test subject should be dry, and in all cases the instrument
should have the capability of being applied to the site in such a manner that
ambient light does not enter the instrument. 

<PAGE>
                                      4

When testing in the manner described above, it is preferred to test for a third
characteristic, as well, and using historical experience, determine whether that
third characteristic lies outside an expected range of values, taking into
account the values measured for the first and second characteristics. When
testing for hyperbilirubinemia in the above procedure, the third characteristic
is Hunter a. If the third characteristic is observed to have a value outside the
range of normal ecpectations this may be an indication of error in the test
procedure, in which case one conducting the test would not want to rely on the
test results.

  Determination of the first and second skin color characteristics at just one
point in time can indicate or strongly suggest a medical condition affecting
skin color if the first characteristic measurement is observed to lie outside a 
range of values for that charactreristic known by experience to be normal for a
subject having the particular measured value of the second characteristic. For
example, in many individuals hyperbilirubinemia is strongly suggested if Hunter
b and L are measured and it is determined that, based on skin color categories
previously observed, Hunter b is above any ordinary value for a subject with
skin having the L value measured. Also, even if baseline readings of Hunter b
and L (and preferably a) are not made, changes in the value of Hunter b can
signal the presence of hyperbilirubinemia in measurements of the Hunter values
are made at timed intervals in the foregoing fashion. Out of the ordinary
increases in Hunter b, of for example two or more points can be an indication of
hyperbilirubinemia when the measured L value remains in a constant range from
one measurement to the next. Similarly, large decreases in Hunter b, of for
example two or more points, can be an indication of hyperbilirubinemia from
which the infant is recovering, again if L remains relatively constant.

  Significant testing has established the value of the foregoing techniques in
detecting hyperbilirubinemia. The same techniques will indicate other
jaundice-producing medical conditions in human and animal subjects. Hepatitis or
liver disorders are examples of such medical conditions susceptible to diagnosis
with the methods and apparatus of this invention.

  Tuberculosis has been observed to affect skin color in dark skinned
individuals such as many persons of African descent. Appropriate color
measurement in accordance with this invention may provide a valuable diagnostic
tool.

  Biopsy specimens, body fluids, excretions, etc. are visually inspected for
color. The techniques and instrumentation according to this invention can
provide objectivity and consistency to such inspections.

  The above and further advantages of this invention will be better understood
with reference to the following detailed description of the preferred embodiment
taken in combination with the attached drawings.


  BRIEF DESCRIPTION OF THE DRAWINGS

  In the Drawings:

  FIG. 1 is a block diagram illustration of an instrument for determining Hunter
L, a and b values and for comparing changes in Hunter b to Hunter b changes
predetermined to be indicative of bilirubinemia.

  FIG. 1a is a diagrammatic illustration of exemplary memory content in an
instrument like that of FIG. 1.

  FIG. 2 is schematic illustration in block diagram form illustrating the steps
in the process of monitoring an infant for hyperbilirubinemia based upon changes
in Hunter b in skin color and including measuring and reviewing Hunter b and L.

<PAGE>

                                  5,671,735

                                      5

     FIG. 3 is a schematic illustration in block diagram form illustrating the
steps in the process of monitoring an infant for hyperbilirubinemia based on
Hunter b including measuring and reviewing Hunter a as well as Hunter b and L.

                         DETAILED DESCRIPTION OF THE
                            PREFERRED EMBODIMENT

     Any modern version of two general types of color-measuring instruments,
colorimeters and spectrophotometers, is an example of instrument suitable for
the skin color measurement according to a preferred embodiment of this 
invention. The basic components of either type of instrument are a light source,
a sample illumination and viewing arrangement, a means of selecting certain
wavelengths of light for the measurement, a detector of the light reflected from
the sample, and some relatively simple computing capacity. In commercially
available instruments the main purposes of the computing capacity are to store
and apply  calibration information and to calculate various color coordinates
for later use. In FIG. 1, a color measuring instrument 10 is illustrated. An
individual person's skin 11 is illuminated by the instrument as generally
indicated by the broken line arrow 12 and the instrument receives illumination
reflected from the skin 11 as generally indicated by the broken arrow 13. Based
on the illumination received by reflection from the skin, the instrument 10
develops the coordinates Y, x and y. In FIG. 1 the instrument 10 is a
colorimeter, commercially available and suitable for development of the values
Y, x and y.

     Another type of instrument that can be used in the skin color
categorization method according to this invention is the spectrophotometer that
measures the skin reflectance at discrete wavelengths and from these data
derives tristimulus values, from which can be computed the Hunter color values
used to measure skin color for diagnostic purposes as discussed below.

     Important to the use of a commercial colorimeter of the kind employed for
the color measurement instrument 10 of FIG. 1 is the calibration of the
instrument using a standard. In the early use of an instrument of this kind by
the inventors, the "Light Skin" sample from the Macbeth Color Checker, described
in the publication of C.S. McCamy, H. Marcus, and J.G. Davidson. "A
Color-Rendition Chart," J. Appl. Photogr. Eng. 2, 95-99 (1976) was used. A tile
of this approximate color was selected for its greater durability as an
instrument standard. It was found, however, that the use of the "Light Skin"
painted paper as the primary standard did not adequately avoid the phenomenon
known as metamerism, by which objects that look alike (have the same perceived
color) under some kinds of light sources or to some observers do not match under
other types of light sources or to other observers. By this phenomenon
colorimeters may not read their colors the same as the average human observer
would under the daylight type light source usually employed for visual
observation, hence leading to an error in colorimeter calibration.

     As an improved primary standard, the skin of a subject whose skin color
measurements were highly reproducible and in the approximate center of the range
of skin colors of the human population was selected. The spectral reflectance
factors of the skin of this subject were carefully measured on a Macbeth 1500
Plus spectrophotometer (Macbeth, New Windsor, N.Y.); these data are given in
column 2 of Table I at the wavelengths listed in column 1. By using
well-established techniques of computer color matching, carried out on an ACS
1800 system equipped with an ACS Spec-

<PAGE>
                                      6

troSensor II color measuring instrument (Datacolor International, Lawrenceville,
N.J.) a colorant formulation matching this skin color was developed. The
spectral reflectance factors for this match are given in column 3 of Table I. It
may be seen that the data closely match those of column 2, indicating the
absence of metamerism. Calculations according to the CIE 1976 CIELAB system
showed that the two data sets match to within 0.27-0.36 units, less than can be
perceived by human color vision, for daylight, incandescent light, and cool
white fluorescent light, the three most commonly used light sources for the
proposed applications.

     The above-mentioned formulation was made up in a stable, durable material
and tiles were prepared as instrument standards. The spectral reflectance
factors of one of these tiles are given in column 4 of Table I. It was found,
however, that the improvement in calibration resulted in color coordinates that
were significantly different from those obtained in the many studies made with
the earlier system. A decision was made to adjust the calibration values of the
new tiles in order to achieve consistent results between the new and old methods
of calibration. Column 5 of Table I gives the adjusted set of spectral
reflectance factors for the tile of column 4. The CIE and Hunter color
coordinates, for measurement with the specular component excluded and calculated
for CIE standard illuminant C and the 1931 2(degree) CIE standard observer, 
are also tabulated for each of the samples in the table.

                                   TABLE I
--------------------------------------------------------------------------------
     Wavelengths,      Skin                           Tile,       Tile, 
        nm.          Standard       Formulation      correct    adjusted
--------------------------------------------------------------------------------

        400           19.03            20.70          21.51       16.67
        420           18.96            20.69          21.10       16.93
        440           21.53            21.68          20.99       17.65
        460           23.36            24.43          23.27       20.56
        480           28.06            28.30          27.82       25.67
        500           30.13            30.77          29.03       27.94
        520           31.19            31.31          29.38       28.24
        540           30.01            30.84          28.48       27.59
        560           31.41            30.76          28.22       27.33
        580           32.85            34.01          31.49       30.12
        600           44.37            43.54          42.58       40.52
        620           51.24            51.57          51.27       47.93
        640           54.56            55.09          55.56       51.10
        660           57.09            57.60          59.22       53.82
        680           58.67            60.41          61.82       56.55
        700           59.95            62.69          63.93       58.87
         X            37.14            37.28          36.14       33.76
         Y            34.66            34.89          33.07       31.53
         X            28.50            28.54          27.63       24.20
         x             0.3703           0.3702         0.3732      0.3732
         y             0.3456           0.3464         0.3415      0.3523
         L            58.87            59.07          57.51       56.15
         a             9.31             9.02          11.54        9.05
         b            12.51            12.70          11.77       13.75
--------------------------------------------------------------------------------

     With a suitable standard, basically, calibration is carried out by forcing
the colorimeter 10 to give the desired color coordinates Y, x and y mentioned
above, while utilizing the colorimeter with the standard tile chosen. The method
of calibration is known for particular instruments and follows a series of steps
prescribed by the manufacturer that need not be detailed here.

     In skin color testing, prior to each test of a subject, each test site is
cleansed. A cleansing agent such as isopropyl alcohol, which leaves behind no
coloration, is suitable. The site is well dried to avoid any wetness which may
interfere with the reflection of light from the skin 11 to the instrument 10. In
all cases of testing, with the instrument correctly calibrated, the measuring
head or instrument orifice is

<PAGE>
                                      7

placed against the test site to be measured. Care is taken to avoid the
admission of ambient light to the instrument. Pressing the head firmly against
the test site prevents the entry of ambient light. Additionally, it was
determined that best results are obtained if one removes the instrument from the
test site briefly, between illuminations. This can be provided for in software
by a conventional delaying routine and, if desired, with an appropriate display
instructing the user to remove the instrument briefly well away from the skin.

  In a colorimeter of the type shown in FIG. 1. at block 10 the instrument has
an internal microprocessor or other computing capability so that it is able to
develop the color coordinates Y, x and y from the measured values X, Y and Z 
(Y being the same in each case). Certain colorimeters develop the Hunter color
coordinates L, a, and b. Since the degreee of computation that the color
measuring device 10 (i.e. colorimeter or spectrophotometer) internally performs
varies, the manner of calculating the Hunter values from the tristimulus
coordinates is useful to an understanding and practice of the invention and will
enable correct use of a CPU by appropriate calculation to perform the invention
with any commercially available colorimeter or spectrophotometer. Most modern
color measuring instruments begin with measurement of the tristimulus vales X,
Y, and Z. From these can be derived the CIE chromaticity coordinates x and y:

                 x=X/(X+Y+Z)                                               (1)

                 y=Y/(X+Y+Z)                                               (2)


The instrument 10 of FIG. 1 outputs the triplet of values x, y and Y as the
starting point for further calculations by a central processing unit which can
be dedicated microprocessor circuitry or personal computer 15. The remaining 
two tristimulus values X and Z are available by computation as follows:

                  X=xY/y,                                                  (3)  

and

                  Z=(1-x-y)Y/y                                             (4)

In the preferred embodiment, in any event, the CPU according to FIG. 1 develops
the Hunter value b discovered in accordance with this invention to be capable of
use to detect and monitor hyperbilirubinemia. The Hunter b value is one of three
values derived by Richard S. Hunter in 1958. Richard S. Hunter, "Photoelectric
Color Difference Meter," J. Opt. Soc. Am. 48, 985-995 (1958). The equations for
these are:

                  L=10 (Y)(to the 1/2 power)                               (5)

                  a=17.5 (1.02 X-Y)/Y(to the 1/2 power)                    (6)

                  b=7.0 (Y-0.847 Z)/Y(to the 1/2 power)                    (7)

where L is a lightness coordinate whose values correlate better with the visual
perceptions of the lightness of object colors than do values of Y; a is a
coordinate denoting redness or greenness, for which positive values denote that
the color is red rather than its opponent color green, and negative values
denote the opposite; and b is a yellowness-blueness

<PAGE>
                                     8

coordinate, for which positive values denote that the color is yellow rather
than the opponent color blue, and negative values of b denote the opposite. For
yellow colors, starting with a=b=0 and an appropriate high value of L, which
would be a light grey, increasing positive values of b result in a series of
colors that may be described as light yellowish grey, pale yellow, light yellow,
brilliant yellow and vivid yellow, in turn. Thus b is a measure of the
"intensity" of the yellow color.

  Historically, all three Hunter values, a, b and L, have been utilized to
describe a color. The inventors have determined that one can use the Hunter skin
lightness measure L and comparative determinations of the Hunter value b
developed at time intervals to measure the jaundice that is symptomatic of
hyperbilirubinemia and by that measurement of jaundice detect the presence or
absence of the ailment. The coordinate b provides a reliable measure of the
yellow undertone of the color of human skin. In the particular arrangement of
FIG. 1, wherein the colorimeter 10 produces the values Y, x, y, the computer 15
derives the Hunter values L and b. The Hunter lightness skin color
characteristic L affects the amount of increase in the yellow measure Hunter b
that indicates hyperbilirubinemia. Following the procedure represented in FIG.
2, steps 1 to 4 and preferably using an averaging technique described below, a
newborn is measured, preferably within 2-5 hours of birth, to establish the
initial, baseline values of Hunter L and b, L(0) and b(0). The values  are
recorded, step 4, for example by placement in machine memory 17. (A baseline
Hunter a, a(0), may be calculated at this time, too, for the purposes explained
below.) Thereafter, again preferably using the averaging technique, throughout
the next several days, Hunter L and b are measured at intervals as represented
by step 5 of FIG. 2. L is compared to the value originally measured as indicated
at step 6. It should not vary more than 3 to 5 points, (depending on the range
of L being measured) or the test is discontinued as at step 7. Otherwise, Hunter
b is compared at step 8 to the baseline value established shortly after birth.
As determined at step 9, if at any time Hunter b increases two points or more
for darker skins with L values at or below approximately 51 or three points 
or more for lighter skins with L value above approximately 51, then
hyperbilirubinemia is indicated and phototherapy, the usual treatment for this
condition, may be prescribed. Alternatively, a blood test may be conducted to
confirm the diagnosis before beginning phototherapy. Hunter b increases of one
to two points for L values at or below approximately 51 and Hunter b increases
of two to three points for L values above approximately 51 can be used as red
flags or warning signs requiring closer monitoring.

  When the measured value of Hunter L at any time is found to have varied more
than 3-5 points the test procedure is suspect and the test may be discontinued.
Hunter L variations of this magnitude do not ordinarily occur in skin color
measurement. The test should be repeated and if the discrepancy is not
eliminated then the comparison of Hunter b values should not be relied upon for
a determination of the presence or absence of hyperbilirubinemia.

  During phototherapy too, the testing procedure according to this invention can
be used. Continued monitoring of Hunter L and b in the above manner can be
utilized until Hunter b is within two points of its baseline value for subjects
whose skin lightness value L is below a particular L value, or within three
points of its baseline for subjects when L is above that value. An L value of
approximately 51 has been found appropriate for this purpose.

  Although it has not been found to affect the measurement of Hunter b or the
reliability of the use of Hunter L and b to

<PAGE>

                                  5,671,735

                                      9

diagnose hyperbilirubinemia, it has been the inventors' practice to require
measurement preferably of Hunter a at each testing. Again the averaging
technique is preferably used as described below. Based upon the testing of the
skin color of several million individuals, the inventors have identified some
210 broad categories of skin coloration. That is to say, 210 broad ranges of
Hunter L, a and b have been identified. Hunter L and b values for each of these
categories are shown in Table II, Appendix A hereto. Table III, below, provides
the ranges of Hunter a reasonably to be expected. For certain values of L,
Hunter a above a particular value has never been observed. Should the test
indicate a Hunter a outside any previously observed range for a particular L
and b, this would be taken as at least an indication of error in testing. This
occurrence is represented at steps 4 and 5 of FIG. 3, which figure represents
the steps in the hyperbilirubinemia test that includes the measurement and
comparison of Hunter a. If retesting does not result in a value of Hunter a
consistent with previous experience, then the use of Hunter L and b as a test
for hyperbilirubinemia in this instance is discontinued.

                                  TABLE III

-------------------------------------------------------------------------------
     If Hunter L values are:                   Then Hunter a values are:
-------------------------------------------------------------------------------
     24 (or less) to 44                               4 to 16
               45 to 54                               4 to 18
               55 to 59                               5 to 25
               60 to 71 (or more)                     6 to 30
-------------------------------------------------------------------------------


    For greater accuracy, multiple Y, x and y readings are made with the
colorimeter 10 at several different sites, for example at one or more locations
on some or all of the subject's forehead, cheek, chest and back, as suggested in
the steps of the method outlined in FIG. 2. In a preferred embodiment 5 or 6
readings at 5 different sites are made. Hunter b and L values are calculated
for each reading. The high and low values of b and associated values of L from
each site are discarded, the computer 15 then averages all of the remaining
values of Hunter b and L. The average b and L thus calculated are then used as
the Hunter b and L values in the previously described testing for bilirubinemia.

    Some variation of b value occurs in dependence on the body location where
readings are taken. Consistently averaging the values of L and b calculated from
measurements taken at the same several locations on each individual can be used
to eliminate any uncertainty resulting from such variations.

    A hospital's measure of serum bilirubin typically uses a scale
different from the measure of Hunter b detected by the above procedure. In
extensive tests at one hospital, a linear relation was observed between
serum bilirubin measured using the hospital's scale and the Hunter b
measurement according to the invention. In that hospital 12 was the
serum bilirubin value that signalled monitoring or treatment of
hyperbilirubinemia.

    Correlation between Hunter b and the hospital bilirubin count (BRC)
was determined to be in accordance with the following equation:

        BRC=2.5 ([{47/L} (to the 1/2 power) b]-6.8)                  (8)

where BRC equals the hospital bilirubin count, the number 47 is the average
L for entire database gathered over the course of research, and L and b
are the average Hunter values determined as described above.

    The term in braces modifies b according to the value L relative to
its average, in this case 47, according to a square 

<PAGE>
                                      10

root (superscript 1/2) function. It may be easier to understand the above
equation if it is written another way. If the modified b (in square brackets) is
called MODB:

        MODB=6.8+0.4 BRC                                             (9)

The numbers 6.8 and 0.4 (=1/2.5 are, respectively, the intercept and
slope of the straight line relation between modified b and BRC. The 6.8
is the value of the MODB when BRC=0 and is related to the average
baseline skin color. The 0.4 shows how rapidly MODB changes as BRC
increases, an increase of 2.5 in BRC raises MODB by one point.

    The equation is exemplary only and may vary in detail when applied
to a larger database or to bilirubin count values from another hospital
since hospitals do not have a standard scale used consistently from one
hospital to the next. However, the linear relationship between MODB and
BRC indicates relatively straightforward conversion of measured L and b
to arrive at a particular hospital's bilirubin count value so that the
medical practitioner can employ the optical measurement of jaundice in
accordance with this invention in the same way she or he employed
bilirubin count previously.

    In the system of FIG. 1, following the routine of FIG.2, from the
initial measurement preferably within 2-5 hours of birth; the CPU
calculates the initial Hunter values L(0), a(0) and b(0) and stores
these in the Baseline Values addresses of the data portion or RAM of
memory 17. The data RAM (or nonprogram) portion 18 of the memory 17 is
indicated in FIG. 1a. A relatively permanent section 18a of RAM 18
stores the data of Table II (and Table III if Hunter a is to be checked)
and data such as the ranges of L that establish catagories of skin
coloration for which varying Hunter b value changes are significant. A
more often revised memory segment stores the results of the measurements
performed with the instrument. Based on a relatively straightforward
program retained in the permanent ROM memory, from the measurements
taken at intervals, the CPU calculates the new values of L and b,
retrieves L(0) and b(0), and subtracts those from the new values of L(1)
and b(1). The change in Hunter L and b, (delta)L and (delta)b, can be
displayed, or preferably, the CPU determines if the change in L
indicates an error by comparing the change in L to that value, stored in
the RAM 18 of the memory 17, that raises the suspicion of test error. If
there is no suspicion of error, then the CPU determines whether an
increase in b is above the value, again stored in memory, that indicates
monitoring or treatment of hyperbilirubinemia for the particular value
of L that has been measured. Similarly, for an infant that has
previously been diagnosed with hyperbilirubinemia and is undergoing
phototherapy, the same order of decrease to within 2 or 3 points of
baseline, depending on L, can indicate recovery and phototherapy may be
ended. The CPU memory 17 can be provided with Table II, or another
compilation of the categories of skin coloration, which the CPU then
can use as a look-up table to determine if Hunter a has a value outside 
of previously observed ranges for the particular Hunter L and b. Also, 
if desired, the CPU can calculate and display the hospital's measure of
serum bilirubin based upon changes in Hunter b, for example by applying
equation 8 above.

    Even in the absence of an initial reading, based on observed ranges
of skin coloration, measurement of Hunter L and b can warn of the
likelihood of hyperbilirubinemia if a Hunter b value is measured that is
in excess of Hunter b ordinarily observed for subjects with that value
of L. Hunter b values exceeding those ordinarily observed for individuals
in a particular range of Hunter L values can be determined

<PAGE>
                                  5,671,735

                                      11

by reference to Table II. For example, it will be apparent that no individual
whose skin has a Hunter L value between 24 and 26 has measured above 13 in
Hunter b. Such a measurement may be used to determine that a blood test is
advisable. In all instances, however, even where there has not been a Hunter b
baseline established, an increase over time of 2,3 or more Hunter b points
indicates the likelihood of hyperbilirubinemia, and if the change is a decrease,
this is indicative of a recovering newborn.

   Table IV is an actual set of measurements made on a three day old infant.
Using the averaging technique described above, Hunter L of 48.0 and Hunter b of
11.1 is calculated. Converting to the hospital bilirubin count in the equation
(9) above, a bilirubin count of 10.5 was calculated.

                                   TABLE IV
--------------------------------------------------------------------------------
                   L         a         b         Y         x         y
--------------------------------------------------------------------------------

  Forehead       47.8      21.6      11.6      22.9      0.411     0.333
                 48.6      19.5      11.5      23.6      0.404     0.335
                 48.8      21.2      11.6      23.8      0.407     0.333
                 46.7      21.6      11.6      21.8      0.413     0.333
                 48.6      21.6      11.8      23.6      0.410     0.333
                 48.0      22.1      11.7      23.1      0.412     0.332
  Forehead       46.4      20.5      11.2      21.5      0.409     0.333
                 46.0      20.3      11.1      21.1      0.409     0.333
                 47.4      21.4      11.6      22.4      0.411     0.333
                 46.1      21.4      10.7      21.2      0.409     0.330
                 46.3      20.4      11.2      21.5      0.409     0.333
                 46.9      20.7      11.3      22.0      0.409     0.333
  Chest          50.5      16.5      11.2      25.5      0.391     0.336
                 50.9      15.3      11.2      25.9      0.388     0.338
                 50.1      17.5      11.2      25.1      0.395     0.336
                 50.7      16.9      11.2      25.7      0.392     0.336
                 50.4      16.4      11.1      25.4      0.391     0.336
                 50.1      17.3      11.1      25.1      0.394     0.335
  Back           49.0      17.1      11.1      24.0      0.395     0.336
                 48.7      16.3      11.0      23.7      0.394     0.337
                 48.3      16.6      10.6      23.3      0.393     0.335
                 49.2      16.6      10.9      24.2      0.393     0.336
                 49.1      18.3      11.3      24.1      0.399     0.335
                 50.0      18.0      11.4      25.0      0.397     0.336
  Back           46.2      15.8      10.5      21.4      0.395     0.337
                 45.3      16.5      10.2      20.5      0.397     0.335
                 45.9      16.0      10.4      21.1      0.395     0.336
                 45.5      14.4      10.3      20.7      0.392     0.338
                 46.3      16.1      11.0      21.4      0.398     0.339
                 47.3      16.9      10.9      22.3      0.397     0.336
--------------------------------------------------------------------------------

   The invention can afford good evidence of jaundice resulting from medical
conditions other than hyperbilirubinemia. Liver disorders in adults and
children produce jaundice, for example. These and other skin color
characteristics can be factors in diagnosing additional diseases that
affect skin color. It has been observed, for example, that at least among
dark skinned individuals, such as African Americans or others of African
descent, skin color is affected by tuberculosis.

   The application of the method and apparatus is not limited to the
jaundice-related testing described above. Experiments with rhesus monkeys
have shown a correlation between hormone levels and the coloration of the
female monkey's very visible reddened hind end. An instrument like that
described above was able to distinguish varying levels of reddening in an
individual test subject's posterior using Hunter a and Hunter L in a
similar fashion to that described above. The hormone level of the subject
was thus indicated by the methods and apparatus of this invention.

   Successful experimentation has begun on the evaluation of the condition
of laboratory mice based upon the use of Hunter a and Hunter L in a
similar fashion to that described above.

   Table V, Appendix B, is a broad categorization of human hair coloration.
Departure of an individual test subject's hair

<PAGE>
                                  12

coloration from a baseline measure can be an indication of a change in the hair
or of greying. In addition to diagnostic use, test procedures and instruments
according to this invention can be used to determine how to restore the hair to
its natural color, or with reference to the categories of Table V, hair that has
changed in color by greying or by bleaching or dying can be restored to a more
natural appearance, whether the test subject's original coloring or a chosen
color consistent with the limitation of the categories identified in Table V.

   In much the same way tooth coloration can be assessed by this invention and
the techniques described can be used to arrive at a natural coloring of
replacement dental work consistent with existing or replacement teeth.

   Plant and crop specimens are good candidates for the application of the
procedures and apparatus of the invention. For example, conditions leading to
the degradation of grain stored in silos are observable based upon color change.
Determination of these conditions by instrument is made possible by the
techniques of the present invention, and this opens the way to automated
monitoring for this purpose. Soil samples from oil spills when measured by these
procedures and apparatus indicate the degree of soil contamination by oil or
gasoline. Testing of such soil contamination has been successfully conducted.
Biological test subjects of a great variety can be tested by means of the
present invention. The color measuring techniques apply to a wide range of
biological test subjects (e.g., hair, teeth, tissue, excretions, foods, soil,
animals, plants).

   From the foregoing it should be apparent that the methods and apparatus
described are exemplary and not intended to limit the scope of protection
of the invention as set forth in the appended claims.

                                   TABLE II
--------------------------------------------------------------------------------
                                  APPENDIX A
                                 ------------
              No.               Hunter L               Hunter b
--------------------------------------------------------------------------------
               1.             less than 27                -5*
               2.             less than 27                 6
               3.             less than 27                 7
               4.             less than 27                 8
               5.             less than 27                 9
               6.             less than 27                10
               7.             less than 27                11
               8.             less than 27                12+**
               9.          27 to less than 30             -5
              10.          27 to less than 30              6
              11.          27 to less than 30              7
              12.          27 to less than 30              8
              13.          27 to less than 30              9
              14.          27 to less than 30             10
              15.          27 to less than 30             11
              16.          27 to less than 30             12+
              17.          30 to less than 33             -5
              18.          30 to less than 33              6
              19.          30 to less than 33              7
              20.          30 to less than 33              8
              21.          30 to less than 33              9
              22.          30 to less than 33             10
              23.          30 to less than 33             11
              24.          30 to less than 33             12+
              25.          33 to less than 36             -5
              26.          33 to less than 36              6
              27.          33 to less than 36              7
              28.          33 to less than 36              8
              29.          33 to less than 36              9
              30.          33 to less than 36             10
              31.          33 to less than 36             11
              32.          33 to less than 36             12+
              33.          36 to less than 39             -5

<PAGE>
                                  5,671,735

                                      13

                              TABLE II-continued
--------------------------------------------------------------------------------
                                  APPENDIX A
                                 ------------
              No.               Hunter L               Hunter b
--------------------------------------------------------------------------------
              34.          36 to less than 39             6
              35.          36 to less than 39             7
              36.          36 to less than 39             8
              37.          36 to less than 39             9
              38.          36 to less than 39            10
              39.          36 to less than 39            11
              40.          36 to less than 39            12
              41.          36 to less than 39            13
              42.          36 to less than 39            14
              43.          36 to less than 39            15+
              44.          39 to less than 42            -5
              45.          39 to less than 42             6
              46.          39 to less than 42             7
              47.          39 to less than 42             8
              48.          39 to less than 42             9
              49.          39 to less than 42            10
              50.          39 to less than 42            11
              51.          39 to less than 42            12
              52.          39 to less than 42            13
              53.          39 to less than 42            14
              54.          39 to less than 42            15+
              55.          42 to less than 45            -5
              56.          42 to less than 45             6
              57.          42 to less than 45             7
              58.          42 to less than 45             8
              59.          42 to less than 45             9
              60.          42 to less than 45            10
              61.          42 to less than 45            11
              62.          42 to less than 45            12
              63.          42 to less than 45            13
              64.          42 to less than 45            14
              65.          42 to less than 45            15
              66.          42 to less than 45            16
              67.          42 to less than 45            17
              68.          42 to less than 45            18+
              69.          45 to less than 48            -5
              70.          45 to less than 48             6
              71.          45 to less than 48             7
              72.          45 to less than 48             8
              73.          45 to less than 48             9
              74.          45 to less than 48            10
              75.          45 to less than 48            11
              76.          45 to less than 48            12
              77.          45 to less than 48            13
              78.          45 to less than 48            14
              79.          45 to less than 48            15
              80.          45 to less than 48            16
              81.          45 to less than 48            17
              82.          45 to less than 48            18+
              83.          48 to less than 51            -5
              84.          48 to less than 51             6
              85.          48 to less than 51             7
              86.          48 to less than 51             8
              87.          48 to less than 51             9
              88.          48 to less than 51            10
              89.          48 to less than 51            11
              90.          48 to less than 51            12
              91.          48 to less than 51            13
              92.          48 to less than 51            14
              93.          48 to less than 51            15
              94.          48 to less than 51            16
              95.          48 to less than 51            17
              96.          48 to less than 51            18
              97.          48 to less than 51            19
              98.          48 to less than 51            20+
              99.          51 to less than 54            -5
             100.          51 to less than 54             6
             101.          51 to less than 54             7
             102.          51 to less than 54             8
             103.          51 to less than 54             9
             104.          51 to less than 54            10
             105.          51 to less than 54            11
             106.          51 to less than 54            12
             107.          51 to less than 54            13
             108.          51 to less than 54            14
 
<PAGE>
                                      14

                              TABLE II-continued
-------------------------------------------------------------------------------
                                  APPENDIX A
                                  ----------

No.                      Hunter L                    Hunter b
-------------------------------------------------------------------------------
              109.         51 to less than 54    15 
              110.         51 to less than 54    16 
              111.         51 to less than 54    17 
              112.         51 to less than 54    18 
              113.         51 to less than 54    19 
              114.         51 to less than 54    20+ 
              115.         54 to less than 57    -5 
              116.         54 to less than 57     6 
              117.         54 to less than 57     7 
              118.         54 to less than 57     8 
              119.         54 to less than 57     9 
              120.         54 to less than 57    10 
              121.         54 to less than 57    11 
              122.         54 to less than 57    12 
              123.         54 to less than 57    13 
              124.         54 to less than 57    14 
              125.         54 to less than 57    15 
              126.         54 to less than 57    16 
              127.         54 to less than 57    17 
              128.         54 to less than 57    18 
              129.         54 to less than 57    19 
              130.         54 to less than 57    20+ 
              131.         57 to less than 60    -5 
              132.         57 to less than 60     6 
              133.         57 to less than 60     7 
              134.         57 to less than 60     8 
              135.         57 to less than 60     9 
              136.         57 to less than 60    10 
              137.         57 to less than 60    11 
              138.         57 to less than 60    12 
              139.         57 to less than 60    13 
              140.         57 to less than 60    14 
              141.         57 to less than 60    15 
              142.         57 to less than 60    16 
              143.         57 to less than 60    17 
              144.         57 to less than 60    18 
              145.         57 to less than 60    19 
              146.         57 to less than 60    20+ 
              147.         60 to less than 63    -5 
              148.         60 to less than 63     6 
              149.         60 to less than 63     7 
              150.         60 to less than 63     8 
              151.         60 to less than 63     9 
              152.         60 to less than 63    10
              153.         60 to less than 63    11
              154.         60 to less than 63    12
              155.         60 to less than 63    13
              156.         60 to less than 63    14
              157.         60 to less than 63    15
              158.         60 to less than 63    16
              159.         60 to less than 63    17
              160.         60 to less than 63    18
              161.         60 to less than 63    19
              162.         60 to less than 63    20+
              163.         63 to less than 66    -5
              164.         63 to less than 66     6
              165.         63 to less than 66     7
              166.         63 to less than 66     8
              167.         63 to less than 66     9
              168.         63 to less than 66    10
              169.         63 to less than 66    11
              170.         63 to less than 66    12
              171.         63 to less than 66    13
              172.         63 to less than 66    14
              173.         63 to less than 66    15
              174.         63 to less than 66    16
              175.         63 to less than 66    17
              176.         63 to less than 66    18
              177.         63 to less than 66    19
              178.         63 to less than 66    20+
              179.         66 to less than 69    -5
              180.         66 to less than 69     6
              181.         66 to less than 69     7
              182.         66 to less than 69     8
              183.         66 to less than 69     9

<PAGE>
                                  5,671,735

                                       15

                               TABLE II-continued
-------------------------------------------------------------------------------
                                  APPENDIX A
                                  ----------

No.                      Hunter L                    Hunter b
-------------------------------------------------------------------------------
184.                66 to less than 69                10
185.                66 to less than 69                11
186.                66 to less than 69                12
187.                66 to less than 69                13
188.                66 to less than 69                14
189.                66 to less than 69                15
190.                66 to less than 69                16
191.                66 to less than 69                17
192.                66 to less than 69                18
193.                66 to less than 69                19
194.                66 to less than 69                20+
195.             less than or equal to 69             -5
196.             less than or equal to 69              6
197.             less than or equal to 69              7
198.             less than or equal to 69              8
199.             less than or equal to 69              9
200.             less than or equal to 69             10
201.             less than or equal to 69             11
202.             less than or equal to 69             12
203.             less than or equal to 69             13
204.             less than or equal to 69             14
205.             less than or equal to 69             15
206.             less than or equal to 69             16
207.             less than or equal to 69             17
208.             less than or equal to 69             18
209.             less than or equal to 69             19
210.             less than or equal to 69             20+
-------------------------------------------------------------------------------
* The designation -5 means less than 5 but more than 4.
** The desidntation 12+ means more than 12 but less than 13.

                                    TABLE V
-------------------------------------------------------------------------------
                                  APPEXDIX B
                                  ----------
CATEGORY                         L                  a                   b
                           -------------      -------------      -------------
Name                       Min      Max        Min     Max         Min     Max
-------------------------------------------------------------------------------
Black                     0.00     14.00     -10.00    3.00      -10.00    5.00
Darkest Dark Brown       14.00     16.00     -10.00    3.00      -10.00    1.00
Darkest Dark Brown       14.00     16.00     -10.00    3.00        1.00    1.15
Darkest Dark Brown       14.00     16.00     -10.00    3.00        1.15    1.25
Darkest Dark Brown       14.00     16.00     -10.00    3.00        1.25    3.00
Darker Dark Brown        16.00     19.00     -10.00    3.00      -10.00    2.70
Darker Dark Brown        16.00     19.00     -10.00    3.00        2.70    2.95
Darker Dark Brown        16.00     19.00     -10.00    3.00        2.95    3.20
Darker Dark Brown        16.00     19.00     -10.00    3.00        3.20   10.00
Darker Dark Brown        16.00     19.00       2.00    3.00      -10.00    2.70
(Cool Auburn Tones)
Darker Dark Brown        16.00     19.00       2.00    3.00        3.20   10.00
(Warm Auburn Tones)
Brown                    19.00     22.00       0.00    6.00      -10.00    2.95
Brown                    19.00     22.00       0.00    6.00        2.95    3.20
Brown                    19.00     22.00       0.00    6.00        3.20    3.45
Brown                    19.00     22.00       0.00    6.00        3.45   10.00
Brown                    19.00     22.00       3.50    6.00        3.45   10.00
(Warm Auburn Tones)
Brown                    19.00     22.00       3.50    6.00      -10.00    3.45
(Cool Auburn Tones)
Medium Brown             22.00     27.00       1.00    6.00      -10.00    3.75
Medium Brown             22.00     27.00       1.00    6.00        3.75    4.00
Golden Med. Brown        22.00     27.00       1.00    6.00        4.00    4.25
Golden Med. Brown        22.00     27.00       1.00    6.00        4.25   10.00
Medium Brown             22.00     27.00       3.50    6.00        4.25   10.00
(Warm Auburn Tones)

<PAGE>
                                      16

                               TABLE V-continued
-------------------------------------------------------------------------------
                                  APPENDIX B
                                  ----------
CATEGORY                         L                  a                   b
                           -------------      -------------      -------------
Name                       Min      Max        Min     Max         Min     Max
-------------------------------------------------------------------------------
Medium Brown             22.00     27.00      3.50     6.00      -10.00    4.25
(Cool Auburn Tones)
Darkest Med. Blonde      27.00     28.00      1.80     6.00       -5.00    6.00
Darkest Med. Blonde      27.00     28.00      1.80     5.00        6.00    6.50
Darkest Med. Blonde      27.00     28.00      5.00     6.00        6.00    6.50
Darkest Med. Blonde      27.00     28.00      1.80     6.00        6.50   15.00
Medium Blonde            28.00     31.00      1.80     6.00       -5.00    6.00
Medium Blonde            28.00     31.00      1.80     5.00        6.00    6.50
Med. Golden Blonde       28.00     31.00      5.00     6.00        6.00    6.50
Med. Golden Blonde       28.00     31.00      1.80     6.00        6.50   15.00
Lightest Med. Blonde     31.00     33.00      1.80     6.00       -5.00    6.00 
Lightest Med. Blonde     31.00     33.00      1.80     5.00        6.00    6.50 
Lightest Med. Blonde     31.00     33.00      5.00     6.00        6.00    6.50 
Lightest Med. Blonde     31.00     33.00      1.80     6.00        6.50   15.00 
Light Blonde             33.00     36.00      1.80     6.00       -5.00    7.00
Light Blonde             33.00     36.00      1.80     5.00        7.00    7.50
Light Blonde             33.00     36.00      5.00     6.00        7.00    7.50
Light Blonde             33.00     36.00      1.80     6.00        7.50   20.00
Lighter Blonde           36.00     40.00      1.80     6.00       -5.00    8.00
Lighter Blonde           36.00     40.00      1.80     5.00        8.00    8.50
Lighter Blonde           36.00     40.00      5.00     6.00        8.00    8.50
Lighter Blonde           36.00     40.00      1.80     6.00        8.50   20.00
Lightest Blonde          40.00     80.00      1.80     7.00       -5.00    9.00
Lightest Blonde          40.00     80.00      1.80     5.00        9.00   10.00
Lightest Blonde          40.00     80.00      5.00     7.00        9.00   10.00
Lightest Blonde          40.00     80.00      1.80     7.00       10.00   30.00
Light Red                22.00     28.00      6.00    30.00       -5.00    3.50
Light Red                22.00     28.00      6.00    30.00        3.50    3.75
Light Red                22.00     28.00      6.00    30.00        3.75    4.00
Light Red                22.00     28.00      6.00    30.00        4.00   30.00
Medium Red               19.00     22.00      6.00    30.00      -10.00    3.50
Medium Red               19.00     22.00      6.00    30.00        3.50    3.75
Med. Golden Red          19.00     22.00      6.00    30.00        3.75    4.00
Med. Golden Red          19.00     22.00      6.00    30.00        4.00   30.00
Dark Red                 14.00     19.00      3.00    30.00      -10.00    2.50
Dark Red                 14.00     19.00      3.00    30.00        2.50    2.75
Dark Red                 14.00     19.00      3.00    30.00        2.75    3.00
Dark Red                 14.00     19.00      3.00    30.00        3.00   30.00
Red Blonde               27.00     40.00      6.00    30.00        6.00   30.00
Red Blonde               40.00     80.00      7.00    30.00        6.00   30.00
Black/Dk                 27.00     50.00    -10.00     1.80      -10.00    3.75
Brown/Med
Brown/Brown
w/70%-90% Grey
Black/Dk                 27.00     50.00    -10.00     1.80        3.75    4.00
Brown/Med
Brown/Brown
w/70%-90% Grey
Black/Dk                 27.00     50.00    -10.00     1.80        4.00    4.25
Brown/Med
Brown/Brown
w/70%-90% Grey
Black/Dk                 27.00     50.00    -10.00     1.80        4.25   10.00
Brown/Med
Brown/Brown
w/70%-90% Grey
Black/Dk                 23.00     27.00    -10.00     1.00      -10.00    3.75
Brown/Med
Brown/Brown
w/40%-60% Grey

<PAGE>
                                  5,671,735

                                      17

                               TABLE V-continued
------------------------------------------------------------------------------
                                  APPENDIX B
                                  ----------
CATEGORY                         L                  a                   b
                           -------------      -------------      -------------
NAME                       Min      Max        Min     Max         Min     Max
-------------------------------------------------------------------------------
Black/Dk                 23.00     27.00     -10.00    1.00        3.75    4.00
Brown/Med
Brown/Brown
w/40%-60% Grey
Black/Dk                 23.00     27.00     -10.00    1.00        4.00    4.25
Brown/Med
Brown/Brown
w/40%-60% Grey
Black/Dk                 23.00     27.00     -10.00    1.00        4.25   10.00
Brown/Med
Brown/Brown
w/40%-60% Grey

                                   Grey Hair
                                   ---------

Light Brown/Darkest Blonde
--------------------------

40%-60% Grey              4.00     10.00     -10.00    -0.08
70%-90% Grey             10.00    to max     -10.00    -0.08
Dark Red, Medium Red or Medium Light Red
----------------------------------------

40%-60% Grey              6.00     10.00     -10.00    -0.08
70%-90% Grey             10.00    to max     -10.00    -0.08
Light Red or Red Blonde
-----------------------

40%-60% Grey              5.00      7.00     -10.00    -0.08
70%-90% Grey              7.00    to max     -10.00    -0.08
Medium to Medium Dark Blonde
----------------------------

40%-60% Grey              1.70      4.00       0.00     0.00
70%-90% Grey              4.00    to max       0.00     0.00
Light Blonde Hair
-----------------

40%-60% Grey            -99.99     -0.25      -1.75    -1.25
70%-90% Grey            -99.99     -0.25     -99.99    -1.75
-------------------------------------------------------------------------------

*Negative values are used in this table in their ordinary sense, to denote
values less than zero.

     We claim:

     1. A process of detecting a condition in a test subject, which condition
includes a symptomatic, detectable change in the test subject's coloration, the
process comprising the steps of:

     (a)  at a first point in time, measuring with a color measuring instrument
          a value of at least one color factor in the test subject's
          coloration, said color factor being dependent, at least in part, on
          relative content of one or more colors in said coloration,

     (b)  waiting an interval,

     (c)  measuring with the color measuring instrument, at least at one
          further point in time, a value of said color factor in the test
          subject's coloration, and

     (d)  comparing the values of said color factor measured at said first and
          said further point in time to determine whether there has been
          exhibited a change therein of a predetermined magnitude evidencing
          said condition, and

     wherein each of steps (a) and (c) comprises measuring the value of a
          color factor that is dependent on relative content of opponent colors
          in said coloration and on lightness of said coloration.

     2. A process of detecting a condition in a test subject, which condition
includes a symptomatic, detectable change in the test subject's coloration, the
process comprising the steps of:

     (a)  at a first point in time, measuring with a color measuring instrument
          a value of at least one color 

<PAGE>
                                      18

          factor in the test subject's coloration, said color factor being 
          dependent, at least in part, on relative content of one  or more 
          colors in said coloration,

     (b)  waiting an interval,

     (c)  measuring with the color measuring instrument, at least at one
          further point in time, a value of said color factor in the test
          subject's coloration, and

     (d)  comparing the values of said color factor measured at said first and
          said further point in time to determine whether there has been
          exhibited a change therein of a predetermined magnitude evidencing
          said condition, and

     wherein each of steps (a) and (c) comprises measuring the value of a color
          factor that comprises a first function weighted in a first portion of
          the spectrum, a second function weighted in a second portion of the
          spectrum, and a weighting term that is a function of lightness of
          said coloration and that modifies the value of the color factor.

     3. The process according to claim 2 wherein measuring the value of the
color factor in each of steps (a) and (c) comprises measuring a factor that is
a first function weighted in a yellower portion of the spectrum and a second
function weighted in a bluer portion of the spectrum.

     4. A process of detecting a condition in a test subject, which condition
includes a symptomatic coloration; the process comprising the steps of:

     (a) measuring with a color measuring instrument a value in the test
         subject's coloration of at least one color factor, said color factor
         being dependent on said coloration and being correlatable, in test
         subjects having colorations of substantially varying degrees of
         lightness or darkness, to a measure of the condition that has clinical
         utility, and

     (b) comparing the measured value of said color factor with a predetermined
         range of values of the color factor to determine whether said measured
         value of said color factor evidences said condition in said test
         subject.

      5. The process according to claim 4 wherein prior to step (b) the process
further comprises the step of establishing the range of values of said color
factor by recording values of Hunter b associated with at least one other color
factor in individuals without said condition, and wherein step (b) comprises
comparing a Hunter b value of the skin coloration of the test subject with the
Hunter b values recorded for individuals comparable with the test subject in
said other color factor of skin coloration.

      6. The process according to claim 4 wherein

     step (b) comprises comparing the measured value of said color factor with a
        range of values of said color factor that is indicative of either the 
        presence or absence of the condition in a subject to determine if the 
        measured value of said color factor lies inside or outside the range.

      7. The process according to claim 6 wherein step (a) comprises measuring
the value of a color factor that is dependent on redness of the coloration of
the test subject.

      8. The process according to claim 4 wherein step (a) comprises measuring
the value of color factor Hunter b, and the process further comprises measuring
th value of said color factor in the coloration of the test subject subsequent
to the first-mentioned measurement, determining any difference between the
first-mentioned and subsequent measurements and comparing said difference to a
range of values to determine whether a change in Hunter b value inside or 
outside said range is present, indicative of either the presence or absence of 
the condition. 

<PAGE>
                                  5,671,735

                                      19

 9. A process of detecting a condition in a test subject, which condition
includes a symptomatic, detectable change in the coloration of the test
subject; the process comprising the steps of:

  (a) at a first point in time, measuring with a color measuring instrument a
      value of relative content of opponent colors in the coloration of the
      test subject.

  (b) waiting an interval.

  (c) measuring with the color measuring instrument, at least at one further
      point in time, a value of relative content of said opponent colors in
      the coloration of the test subject, and

  (d) comparing the values measured at said first and said further points in
      time to determine whether there has been exhibited a change therein of
      a predetermined magnitude that evidences said condition and that is
      correltable, in test subjects having colorations of substantially varying
      degrees of lightness or darkness, to a measure of said condition that has
      clinical utility.

10. The process according to claim 9 wherein each of steps (a) and (c) comprises
measuring the value of a color factor that is dependent on lightness of the
coloration of the test subject and that modifies the value of the relative
content of the opponent colors in said coloration.

11. A process of detecting a condition in a test subject, which condition
includes a symptomatic, detectable change in the test subject's coloration; the
process comprising the steps of:

  (a) at a first point in time, measuring with a color measuring instrument a
      value of at least one color factor in the test subject's coloration, said
      color factor being dependent, at least in part, on relative content of
      one or more colors in said coloration.

  (b) waiting an interval,

  (c) measuring with the color measuring instrument, at least at one further 
      point in time, a value of said color factor in the test subject's 
      coloration,

  (d) comparing the values of said color factor measured at said first and said
      further point in time to arrive at a value of change in color factor, and

  (e) comparing the value of change in color factor with a preestablished
      measure of color factor value change that is known to evidence said
      condition and that is correlatable, in test subjects having colorations of
      substantially varying degrees of lightness or darkness, to a measure of
      the condition that has clinical utility.

12. A process of detecting a condition in a test subject, which condition
includes a symptomatic, detectable change in the test subject's coloration; the
process comprising the steps of:

  (a) at a first point in time, measuring with a color measuring instrument a
      value of at least one color factor Hunter b in the test subject's
      coloration, said color factor Hunter b being dependent, at least in part,
      on relative content of one or more colors in said coloration, 

  (b) waiting an interval,

  (c) measuring with the color measuring instrument, at least at one further
      point in time, a value of said color factor Hunter b in the test subject's
      coloration, and 

  (d) comparing the values of said color factor Hunter b measured at said first
      and further points in time to determine whether there has been exhibited a
      change therein of a predetermined magnitude evidencing said condition. 

<PAGE>
                                      20

13. A process of detecting the jaundice caused by hyperbilirubinemia in an
infant test subject, which jaundice includes a symptomatic, detectable change in
the infant's coloration; the process comprising the steps of:

  (a) establishing a baseline measurement for said infant by measuring with a
      color measuring instrument a value of at least one color factor in the
      infant's coloration at a first point in time following birth when jaundice
      resulting from hyperbilirubinemia is generally not present in an infant,
      said color factor being  dependent, at least in part, on relative content
      of one or more colors in said coloration,

  (b) waiting an interval,

  (c) measuring with the color measuring instrument, at least at one further
      point in time, a value of said color factor in the infant's coloration, 
      and
      
  (d) comparing the value of said color factor baseline measurement at said
      first point in time and said value of said color factor at the further
      point in time to determine whether there has been exhibited a change
      therein of a predetermined magnitude for that particular infant.

14. A process of detecting a condition in a test subject, which condition
includes a symptomatic, detectable change in the test subject's coloration; the
process comprising the steps of:

  (a) establishing a plurality of coloration classes in which a predetermined
      magnitude of a change in value of at least one color factor is indicative
      of the condition, said predetermined  magnitude indicative of the
      condition differing from one coloration class to another.

  (b) at a first point in time, measuring with a color measuring instrument a
      value of the at least one color factor in the test subject's coloration,
      said color factor being dependent, at least in part, on relative content
      of one or more colors in said coloration.

  (c) waiting an interval

  (d) measuring with the color instrument, at least at one further point in
      time, a value of said color factor in the test subject's coloration, and

  (e) comparing the values of said color factor measured at said first and said
      further points in time to determine whether there has been exhibited a
      change therein of the predetermined magnitude evidencing said condition
      for the particular coloration class of the test subject.

15. The process according to claim 14 wherein the step of establishing a
plurality of coloration classes comprises establishing a plurality of coloration
classes that are colorations within varying ranges of lightness.

16. The process according to claim 15 wherein the color factor is Hunter b and
the coloration classes are defined by ranges of values of Hunter L, the process
further comprising the step of measuring by instrument a Hunter L value of the
test subject's coloration.

17. The process according to claim 16 wherein the coloration is skin coloration
and the step of establishing a plurality of coloration classes comprises
establishing coloration classes that include a first class of skin coloration
having a Hunter L value at or below substantially 51 and a second class of skin
coloration having a Hunter L value above substantially 51, wherein increases in
Hunter b values of substantially two or more points for skin coloration of the
first class are indicative of hyperbilirubinemia, and wherein increases in
Hunter b values of substantially three or more points for skin coloration of the
second class are indicative of hyperbilirubinemia.


<PAGE>
                                  5,671,735

                                      21

  18. The process according to either                                  
claim 16, or 17 wherein said coloration                               
classes are substantially as follows:                                 
------------- --------------------------------                                
  No.          Hunter L             Hunter b                                    
----------------------------------------------                                
   1.        less than 27             -5*                                       
   2.        less than 27              6                                        
   3.        less than 27              7                                        
   4.        less than 27              8                                        
   5.        less than 27              9                                        
   6.        less than 27             10                                        
   7.        less than 27             11                                        
   8.        less than 27             12+**                                     
   9.     27 to less than 30          -5                                        
  10.     27 to less than 30           6                                        
  11.     27 to less than 30           7                                        
  12.     27 to less than 30           8                                        
  13.     27 to less than 30           9                                        
  14.     27 to less than 30          10                                        
  15.     27 to less than 30          11                                        
  16.     27 to less than 30          12+                                       
  17.     30 to less than 33          -5                                        
  18.     30 to less than 33           6                                        
  19.     30 to less than 33           7                                        
  20.     30 to less than 33           8                                        
  21.     30 to less than 33           9                                        
  22.     30 to less than 33          10                                        
  23.     30 to less than 33          11                                        
  24.     30 to less than 33          12+                                       
  25.     33 to less than 36          -5                                        
  26.     33 to less than 36           6                                        
  27.     33 to less than 36           7                                        
  28.     33 to less than 36           8                                        
  29.     33 to less than 36           9                                        
  30.     33 to less than 36          10                                        
  31.     33 to less than 36          11                                        
  32.     33 to less than 36          12+                                       
  33.     36 to less than 39          -5                                        
  34.     36 to less than 39           6                                        
  35.     36 to less than 39           7                                        
  36.     36 to less than 39           8                                        
  37.     36 to less than 39           9                                        
  38.     36 to less than 39          10                                        
  39.     36 to less than 39          11                                        
  40.     36 to less than 39          12                                        
  41.     36 to less than 39          13                                        
  42.     36 to less than 39          14                                        
  43.     36 to less than 39          15+                                       
  44.     39 to less than 42          -5                                        
  45.     39 to less than 42           6                                        
  46.     39 to less than 42           7                                        
  47.     39 to less than 42           8                                        
  48.     39 to less than 42           9                                        
  49.     39 to less than 42          10                                        
  50.     39 to less than 42          11                                        
  51.     39 to less than 42          12                                        
  52.     39 to -42                   13                                        
  53.     39 to less than 42          14                                        
  54.     39 to less than 42          15+                                       
  55.     42 to -45                   -5                                        
  56.     42 to less than 45           6                                        
  57.     42 to less than 45           7                                        
  58.     42 to less than 45           8                                        
  59.     42 to less than 45           9                                        
  60.     42 to less than 45          10                                        
  61.     42 to less than 45          11                                        
  62.     42 to less than 45          12                                        
  63.     42 to less than 45          13                                        
  64.     42 to less than 45          14                                        
  65.     42 to less than 45          15                                        
  66.     42 to less than 45          16                                        
  67.     42 to less than 45          17                                        
  68.     42 to less than 45          18+                                       
  69.     45 to less than 48          -5                                        
  70.     45 to less than 48           6                                        
  71.     45 to less than 48           7                                        
  72.     45 to less than 48           8                                        
  73.     45 to less than 48           9                                        
  74.     45 to less than 48          10                                        
  75.     45 to less than 48          11
                                                                       
<PAGE>
                                      22
                                  -continued

   ------------------------------------------
    No.            Hunter L        Hunter b
   ------------------------------------------
    76.      45 to less than 48       12
    77.      45 to less than 48       13
    78.      45 to less than 48       14
    79.      45 to less than 48       15
    80.      45 to less than 48       16
    81.      45 to less than 48       17
    82.      45 to less than 48       18+
    83.      48 to less than 51       -5
    84.      48 to less than 51        6
    85.      48 to less than 51        7
    86.      48 to less than 51        8
    87.      48 to less than 51        9
    88.      48 to less than 51       10
    89.      48 to less than 51       11
    90.      48 to less than 51       12
    91.      48 to less than 51       13
    92.      48 to less than 51       14
    93.      48 to less than 51       15
    94.      48 to less than 51       16
    95.      48 to less than 51       17
    96.      48 to less than 51       18
    97.      48 to less than 51       19
    98.      48 to less than 51       20+
    99.      51 to less than 54       -5
   100.      51 to less than 54        6
   101.      51 to less than 54        7
   102.      51 to less than 54        8
   103.      51 to less than 54        9
   104.      51 to less than 54       10
   105.      51 to less than 54       11
   106.      51 to less than 54       12
   107.      51 to less than 54       13
   108.      51 to less than 54       14
   109.      51 to less than 54       15
   110.      51 to less than 54       16
   111.      51 to less than 54       17
   112.      51 to less than 54       18
   113.      51 to less than 54       19
   114.      51 to less than 54       20+
   115.      54 to less than 57       -5
   116.      54 to less than 57        6
   117.      54 to less than 57        7
   118.      54 to less than 57        8
   119.      54 to less than 57        9
   120.      54 to less than 57       10
   121.      54 to less than 57       11
   122.      54 to less than 57       12
   123.      54 to less than 57       13
   124.      54 to less than 57       14
   125.      54 to less than 57       15
   126.      54 to less than 57       16
   127.      54 to less than 57       17
   128.      54 to less than 57       18
   129.      54 to less than 57       19
   130.      54 to less than 57       20+
   131.      57 to less than 60       -5
   132.      57 to less than 60        6
   133.      57 to less than 60        7
   134.      57 to less than 60        8
   135.      57 to less than 60        9
   136.      57 to less than 60       10
   137.      57 to less than 60       11
   138.      57 to less than 60       12
   139.      57 to less than 60       13
   140.      57 to less than 60       14
   141.      57 to less than 60       15
   142.      57 to less than 60       16
   143.      57 to less than 60       17
   144.      57 to less than 60       18
   145.      57 to less than 60       19
   146.      57 to less than 60       20+
   147.      60 to less than 63       -5
   148.      60 to less than 63        6
   149.      60 to less than 63        7
   150.      60 to less than 63        8
   151.      60 to less than 63        9
   152.      60 to less than 63       10
   153.      60 to less than 63       11

<PAGE>
                                  5,671,735

                                      23
                                  -continued

-----------------------------------------------------
     No.         Hunter L                 Hunter b
-----------------------------------------------------
    154.   60 to less than 63                 12
    155.   60 to less than 63                 13
    156.   60 to less than 63                 14
    157.   60 to less than 63                 15
    158.   60 to less than 63                 16
    159.   60 to less than 63                 17
    160.   60 to less than 63                 18
    161.   60 to less than 63                 19
    162.   60 to less than 63                 20+
    163.   63 to less than 66                 -5
    164.   63 to less than 66                  6
    165.   63 to less than 66                  7
    166.   63 to less than 66                  8
    167.   63 to less than 66                  9
    168.   63 to less than 66                 10
    169.   63 to less than 66                 11
    170.   63 to less than 66                 12
    171.   63 to less than 66                 13
    172.   63 to less than 66                 14
    173.   63 to less than 66                 15
    174.   63 to less than 66                 16
    175.   63 to less than 66                 17
    176.   63 to less than 66                 18
    177.   63 to less than 66                 19
    178.   63 to less than 66                 20+
    179.   66 to less than 69                 -5
    180.   66 to less than 69                  6
    181.   66 to less than 69                  7
    182.   66 to less than 69                  8
    183.   66 to less than 69                  9
    184.   66 to less than 69                 10
    185.   66 to less than 69                 11
    186.   66 to less than 69                 12
    187.   66 to less than 69                 13
    188.   66 to less than 69                 14
    189.   66 to less than 69                 15
    190.   66 to less than 69                 16
    191.   66 to less than 69                 17
    192.   66 to less than 69                 18
    193.   66 to less than 69                 19
    194.   66 to less than 69                 20+
    195.   greater than or equal to 69        -5
    196.   greater than or equal to 69         6
    197.   greater than or equal to 69         7
    198.   greater than or equal to 69         8
    199.   greater than or equal to 69         9
    200.   greater than or equal to 69        10
    201.   greater than or equal to 69        11
    202.   greater than or equal to 69        12
    203.   greater than or equal to 69        13
    204.   greater than or equal to 69        14
    205.   greater than or equal to 69        15
    206.   greater than or equal to 69        16
    207.   greater than or equal to 69        17
    208.   greater than or equal to 69        18
    209.   greater than or equal to 69        19
    210.   greater than or equal to 69        20+
-----------------------------------------------------

wherein -5 represents a value less than 5 but more than 4, and 12+, 15+, 18+,
and 20+ represent a value more than 12, 15, 18, and 20, respectively, but less
than 13, 16, 19, and 21, respectively.

  19. The process according to either claim 15 or 14 wherein said coloration
classes are determined by ranges of Hunter L values; said ranges of Hunter L
values being bounded by at least one of the Hunter L values substantially as
follows:

  Hunter L=27, 30, 33, 36, 39, 42, 45, 48, 54, 57, 60, 63, 66 and 69.

  20. The process according to claim 14 wherein each of steps (b) and (d)
comprises measuring the value of said color factor at different locations on the
test subject.

  21. The process according to claim 14 wherein each of steps (b) and (d)
comprises making a set of multiple mea-

<PAGE>
                                      24

surements of the color factor value at each of the respective points in time 
and averaging each set of multiple measurements.

  22. A process of detecting a medical condition, which condition includes a
symptomatic, detectable change in a test subject's coloration; the process
comprising the steps of:

  (a) establishing a baseline measurement for said test subject by measuring 
      with a color measuring instrument a value of at least one color factor
      in the test subject's coloration at a first point in time when the
      symptomatic, detectable change in coloration resulting from the medical
      condition is generally not present in a test subject, said color factor 
      being dependent, at least in part, on relative content of one or more
      colors in said coloration,

  (b) waiting an interval,

  (c) measuring with the color measuring instrument, at least one further point 
      in time, a value of said color factor in the test subject's coloration,
      and    
             
  (d) comparing the value of said color factor baseline measurement at said
      first point in time and said value of said color factor at the further
      point in time to determine whether there has been exhibited a change
      therein of a predetermined magnitude for that particular test subject.

  23. The process according to any one of claims 1, 13 or 22 wherein each of 
steps (a) and (c) comprises measuring the value of a color factor that 
comprises a first function weighted in a yellower portion of the spectrum and a
second function weighted in a bluer portion of the spectrum.

  24. The process according to any one of claims 1, 4, or 22 wherein step (a)
comprises measuring the value of color factor Hunter a.

  25. A process of detecting the condition of a test subject based on 
coloration of said test subject; the process comprising the steps of:

  (a) measuring with a color measuring instrument the value of at least one
      color factor Hunter b in said coloration of the test subject, and

  (b) comparing the measured value of said color factor Hunter b with a range of
      values of Hunter b that are indicative of either the presence or absence
      of the condition in a subject to determine if the measured value of said 
      color factor lies inside or outside the range.

  26. A process of detecting a condition in a test subject, which condition
includes a symptomatic coloration; the process comprising the steps of:

  (a) measuring with a color measuring instrument a value of at least one color
      factor. Hunter b, in the test subject's coloration, said color factor
      being dependent on said coloration,

  (b) comparing the measured value of said color factor with a predetermined
      range of values of the color factor to determine whether said measured 
      value of said color factor evidences said condition in said test subject,

  (c) measuring the value of said color factor in the coloration of the test 
      subject subsequent to the first-mentioned measurement,

  (d) determining any difference between the first-mentioned and subsequent
      measurements, and

  (e) comparing said difference to a range of values of change of Hunter b to
      determine whether a change in Hunter b value inside or outside said range
      is present, indicative of either the presence or absence of the condition.

<PAGE>
                                  5,671,735

                                      25

   50. The process according to claim 47 wherein the process of detecting a
condition in a biological test subject comprises detecting a condition in a
biological test subject that is selected from the group consisting of plants
and soil.
   51. The process according to claim 47 wherein the process of detecting a
condition in a biological test subject comprises detecting a condition in a
biological test subject selected from the group consisting of tissue,
excretions, body fluids, hair, and teeth.
   52. The process according to any one of claims 1,2 ,4, 9, 11, 12, 14, 22,
25, 26, 29 or 44 wherein said process of detecting a condition in a test
subject comprises a process of detecting a condition selected from the group
consisting of liver disorders, hypertension, and tuberculosis.
   53. The process according to claim 44 wherein step (a) comprises assembling
the group of lightness measure value ranges in machine-readable, tangible
form, and step (b) comprises associating the color factor value with each
lightness measure value range in said machine-readable, tangible form.
   54. The process according to claim 53 wherein step(b) comprises associating
a value of color factor Hunter b with each lightness measure value range.
   55. the process according to claim 54 wherein step (a) comprises compiling
a group of values of lightness measure Hunter L.
   56. The process according to claim 44, wherein step (a) comprises compiling
a group of lightness measure color factor values that are substantially those
of color factor Hunter L and step (b) comprises associating a value of at
least one further color factor whose value is substantially that of color
factor Hunter a with each lightness measure color factor value range, the
relationship between said lightness measure color factor value ranges and said
associated color factor values being substantially as follows:

--------------------------------------------------------------------------------
                                        Hunter L                  Hunter a 
--------------------------------------------------------------------------------


                                    24 (or less) to 44             4 to 16 
                                              45 to 54             4 to 18 
                                              55 to 59             5 to 25 
                                              60 to 71 (or more)   6 to 30.
--------------------------------------------------------------------------------

   57. The process according to claim 44 wherein step (b) comprises associating
with each lightness measure value range a value of a yellowness-dependent color
factor. 
   58. The process according to claim 44 wherein the color factor is Hunter b
and the lightness measure value ranges are ranges of Hunter L, the process
further comprising the step of measuring by instrument a Hunter L value of the
test subject's coloration.
   59. The process according to either claim 5 or 44 wherein said ranges of
values are determined by ranges of Hunter L values; said ranges of Hunter L
values being bounded by at least one of the Hunter L values substantially as
follows:
     Hunter L=27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60, 63, 66 and 69.
   60. A process of detecting hyperbilirubinemia in a test subject based on
skin coloration of said test subject; the process comprising the steps of:
     (a)  measuring with a color measuring instrument a value of a first color
          factor whose value is substantially that of Hunter b in said skin
          coloration of the test subject.
     (b)  measuring with a color measuring instrument a value of a second
          color factor whose value is substantially that of Hunter L in said
          skin coloration of the test subject; and

<PAGE>
                                      26

     (c)  comparing the measured value of said first color factor with a range
          of acceptable values of said first color factor that are found in
          subjects in the absence of hyperbilirubinemia, said subjects having
          a skin coloration corresponding to the particular measured value of
          said second color factor in said test subject to determine if the
          measured value of said first color factor lies inside or outside the
          range, wherein said range of acceptable values is selected from
          ranges substantially as follows:

--------------------------------------------------------------------------------
              No.                Hunter L               Hunter b
--------------------------------------------------------------------------------
               1.               less than 27               -5*
               2.               less than 27                6
               3.               less than 27                7
               4.               less than 27                8
               5.               less than 27                9
               6.               less than 27               10
               7.               less than 27               11
               8.               less than 27               12+**
               9.            27 to less than 30            -5
              10.            27 to less than 30             6
              11.            27 to less than 30             7
              12.            27 to less than 30             8
              13.            27 to less than 30             9
              14.            27 to less than 30            10
              15.            27 to less than 30            11
              16.            27 to less than 30            12+
              17.            30 to less than 33            -5
              18.            30 to less than 33             6
              19.            30 to less than 33             7
              20.            30 to less than 33             8
              21.            30 to less than 33             9
              22.            30 to less than 33            10
              23.            30 to less than 33            11
              24.            30 to less than 33            12+
              25.            33 to less than 36            -5
              26.            33 to less than 36             6
              27.            33 to less than 36             7
              28.            33 to less than 36             8
              29.            33 to less than 36             9
              30.            33 to less than 36            10
              31.            33 to less than 36            11
              32.            33 to less than 36            12+
              33.            36 to less than 39            -5
              34.            36 to less than 39             6
              35.            36 to less than 39             7
              36.            36 to less than 39             8
              37.            36 to less than 39             9
              38.            36 to less than 39            10
              39.            36 to less than 39            11
              40.            36 to less than 39            12
              41.            36 to less than 39            13
              42.            36 to less than 39            14
              43.            36 to less than 39            15+
              44.            39 to less than 42            -5
              45.            39 to less than 42             6
              46.            39 to less than 42             7
              47.            39 to less than 42             8
              48.            39 to less than 42             9
              49.            39 to less than 42            10
              50.            39 to less than 42            11
              51.            39 to less than 42            12
              52.            39 to less than 42            13
              53.            39 to less than 42            14
              54.            39 to less than 42            15+
              55.            42 to less than 45            -5
              56.            42 to less than 45             6
              57.            42 to less than 45             7
              58.            42 to less than 45             8
              59.            42 to less than 45             9
              60.            42 to less than 45            10
              61.            42 to less than 45            11
              62.            42 to less than 45            12
              63.            42 to less than 45            13
              64.            42 to less than 45            14
              65.            42 to less than 45            15
              66.            42 to less than 45            16

<PAGE>
                                   5,671,735

                                      27
                                  -continued

--------------------------------------------------------------------------------
              No.                Hunter L               Hunter b
--------------------------------------------------------------------------------
               67.             42 to less than 45            17
               68.             42 to less than 45            18+
               69.             45 to less than 48            -5
               70.             45 to less than 48             6
               71.             45 to less than 48             7
               72.             45 to less than 48             8
               73.             45 to less than 48             9
               74.             45 to less than 48            10
               75.             45 to less than 48            11
               76.             45 to less than 48            12
               77.             45 to less than 48            13
               78.             45 to less than 48            14
               79.             45 to less than 48            15
               80.             45 to less than 48            16
               81.             45 to less than 48            17
               82.             45 to less than 48            18+
               83.             48 to less than 51            -5
               84.             48 to less than 51             6
               85.             48 to less than 51             7
               86.             48 to less than 51             8
               87.             48 to less than 51             9
               88.             48 to less than 51            10
               89.             48 to less than 51            11
               90.             48 to less than 51            12
               91.             48 to less than 51            13
               92.             48 to less than 51            14
               93.             48 to less than 51            15
               94.             48 to less than 51            16
               95.             48 to less than 51            17
               96.             48 to less than 51            18
               97.             48 to less than 51            19
               98.             48 to less than 51            20+
               99.             51 to less than 54            -5
              100.             51 to less than 54             6
              101.             51 to less than 54             7
              102.             51 to less than 54             8
              103.             51 to less than 54             9
              104.             51 to less than 54            10
              105.             51 to less than 54            11
              106.             51 to less than 54            12
              107.             51 to less than 54            13
              108.             51 to less than 54            14
              109.             51 to less than 54            15
              110.             51 to less than 54            16
              111.             51 to less than 54            17
              112.             51 to less than 54            18
              113.             51 to less than 54            19
              114.             51 to less than 54            20+
              115.             54 to less than 57            -5
              116.             54 to less than 57             6
              117.             54 to less than 57             7
              118.             54 to less than 57             8
              119.             54 to less than 57             9
              120.             54 to less than 57            10
              121.             54 to less than 57            11
              122.             54 to less than 57            12
              123.             54 to less than 57            13
              124.             54 to less than 57            14
              125.             54 to less than 57            15
              126.             54 to less than 57            16
              127.             54 to less than 57            17
              128.             54 to less than 57            18
              129.             54 to less than 57            19
              130.             54 to less than 57            20+
              131.             57 to less than 60            -5
              132.             57 to less than 60             6
              133.             57 to less than 60             7
              134.             57 to less than 60             8
              135.             57 to less than 60             9
              136.             57 to less than 60            10
              137.             57 to less than 60            11
              138.             57 to less than 60            12
              139.             57 to less than 60            13
              140.             57 to less than 60            14
              141.             57 to less than 60            15
              142.             57 to less than 60            16
              143.             57 to less than 60            17
              144.             57 to less than 60            18

<PAGE>
                                      28
                                  -continued

--------------------------------------------------------------------------------
              No.                Hunter L               Hunter b
--------------------------------------------------------------------------------

              145.             57 to less than 60            19
              146.             57 to less than 60            20+
              147.             60 to less than 63            -5
              148.             60 to less than 63             6
              149.             60 to less than 63             7
              150.             60 to less than 63             8
              151.             60 to less than 63             9
              152.             60 to less than 63            10
              153.             60 to less than 63            11
              154.             60 to less than 63            12
              155.             60 to less than 63            13
              156.             60 to less than 63            14
              157.             60 to less than 63            15
              158.             60 to less than 63            16
              159.             60 to less than 63            17
              160.             60 to less than 63            18
              161.             60 to less than 63            19
              162.             60 to less than 63            20+
              163.             63 to less than 66            -5
              164.             63 to less than 66             6
              165.             63 to less than 66             7
              166.             63 to less than 66             8
              167.             63 to less than 66             9
              168.             63 to less than 66            10
              169.             63 to less than 66            11
              170.             63 to less than 66            12
              171.             63 to less than 66            13
              172.             63 to less than 66            14
              173.             63 to less than 66            15
              174.             63 to less than 66            16
              175.             63 to less than 66            17
              176.             63 to less than 66            18
              177.             63 to less than 66            19
              178.             63 to less than 66            20+
              179.             66 to less than 69            -5
              180.             66 to less than 69             6
              181.             66 to less than 69             7
              182.             66 to less than 69             8
              183.             66 to less than 69             9
              184.             66 to less than 69            10
              185.             66 to less than 69            11
              186.             66 to less than 69            12
              187.             66 to less than 69            13
              188.             66 to less than 69            14
              189.             66 to less than 69            15
              190.             66 to less than 69            16
              191.             66 to less than 69            17
              192.             66 to less than 69            18
              193.             66 to less than 69            19
              194.             66 to less than 69            20+
              195.         greater than or equal to 69       -5
              196.         greater than or equal to 69        6
              197.         greater than or equal to 69        7
              198.         greater than or equal to 69        8
              199.         greater than or equal to 69        9
              200.         greater than or equal to 69       10
              201.         greater than or equal to 69       11
              202.         greater than or equal to 69       12
              203.         greater than or equal to 69       13
              204.         greater than or equal to 69       14
              205.         greater than or equal to 69       15
              206.         greater than or equal to 69       16
              207.         greater than or equal to 69       17
              208.         greater than or equal to 69       18
              209.         greater than or equal to 69       19
              210.         greater than or equal to 69       20+

--------------------------------------------------------------------------------
Wherein the designation -5 means less than 5 but more than 4 and the
designation +12 means more than 12 but less than 13.
   61. In a process for determining a color characteristic, the improvement
comprising the steps of:

   (a)  compiling a group of lightness measure color factor value ranges,
        said lightness measure color factor comprising a color factor whose
        value is substantially that of color factor Hunter L, and

<PAGE>
                                      29

(b) associating with each lightness measure color factor value range a value of
at least one further color factor for use in comparison with a measurement of
the value of that color factor in the coloration of a test subject having a
lightness measure color factor value in said range, said at least one further
color factor comprising a color factor whose value is substantially that of
color factor Hunter b and the relationship between said lightness measure color
factor value ranges and said associated color factor values being substantially
as follows:

----------------------------------------
  No.           Hunter L       Hunter b
----------------------------------------
    1.          less than 27    -5*
    2.          less than 27     6
    3.          less than 27     7
    4.          less than 27     8
    5.          less than 27     9
    6.          less than 27    10
    7.          less than 27    11
    8.          less than 27    12+**
    9.    27 to less than 30    -5
   10.    27 to less than 30     6
   11.    27 to less than 30     7
   12.    27 to less than 30     8
   13.    27 to less than 30     9
   14.    27 to less than 30    10
   15.    27 to less than 30    11
   16.    27 to less than 30    12+
   17.    30 to less than 33    -5
   18.    30 to less than 33     6
   19.    30 to less than 33     7
   20.    30 to less than 33     8
   21.    30 to less than 33     9
   22.    30 to less than 33    10
   23.    30 to less than 33    11
   24.    30 to less than 33    12+
   25.    33 to less than 36    -5
   26.    33 to less than 36     6
   27.    33 to less than 36     7
   28.    33 to less than 36     8
   29.    33 to less than 36     9
   30.    33 to less than 36    10
   31.    33 to less than 36    11
   32.    33 to less than 36    12+
   33.    36 to less than 39    -5
   34.    36 to less than 39     6
   35.    36 to less than 39     7
   36.    36 to less than 39     8
   37.    36 to less than 39     9
   38.    36 to less than 39    10
   39.    36 to less than 39    11
   40.    36 to less than 39    12
   41.    36 to less than 39    13
   42.    36 to less than 39    14
   43.    36 to less than 39    15+
   44.    39 to less than 42    -5
   45.    39 to less than 42     6
   46.    39 to less than 42     7
   47.    39 to less than 42     8
   48.    39 to less than 42     9
   49.    39 to less than 42    10
   50.    39 to less than 42    11
   51.    39 to less than 42    12
   52.    39 to less than 42    13
   53.    39 to less than 42    14
   54.    39 to less than 42    15+
   55.    42 to less than 45    -5
   56.    42 to less than 45     6
   57.    42 to less than 45     7
   58.    42 to less than 45     8
   59.    42 to less than 45     9
   60.    42 to less than 45    10
   61.    42 to less than 45    11
   62.    42 to less than 45    12
   63.    42 to less than 45    13
   64.    42 to less than 45    14

<PAGE>
                                      30
                                  -continued

----------------------------------------
  No.           Hunter L       Hunter b
----------------------------------------

   65.    42 to less than 45    15
   66.    42 to less than 45    16
   67.    42 to less than 45    17
   68.    42 to less than 45    18+
   69.    45 to less than 48    -5
   70.    45 to less than 48     6
   71.    45 to less than 48     7
   72.    45 to less than 48     8
   73.    45 to less than 48     9
   74.    45 to less than 48    10
   75.    45 to less than 48    11
   76.    45 to less than 48    12
   77.    45 to less than 48    13
   78.    45 to less than 48    14
   79.    45 to less than 48    15
   80.    45 to less than 48    16
   81.    45 to less than 48    17
   82.    45 to less than 48    18+
   83.    48 to less than 51    -5
   84.    48 to less than 51     6
   85.    48 to less than 51     7
   86.    48 to less than 51     8
   87.    48 to less than 51     9
   88.    48 to less than 51    10
   89.    48 to less than 51    11
   90.    48 to less than 51    12
   91.    48 to less than 51    13
   92.    48 to less than 51    14
   93.    48 to less than 51    15
   94.    48 to less than 51    16
   95.    48 to less than 51    17
   96.    48 to less than 51    18
   97.    48 to less than 51    19
   98.    48 to less than 51    20+
   99.    51 to less than 54    -5
  100.    51 to less than 54     6
  101.    51 to less than 54     7
  102.    51 to less than 54     8
  103.    51 to less than 54     9
  104.    51 to less than 54    10
  105.    51 to less than 54    11
  106.    51 to less than 54    12
  107.    51 to less than 54    13
  108.    51 to less than 54    14
  109.    51 to less than 54    15
  110.    51 to less than 54    16
  111.    51 to less than 54    17
  112.    51 to less than 54    18
  113.    51 to less than 54    19
  114.    51 to less than 54    20+
  115.    54 to less than 57    -5
  116.    54 to less than 57     6
  117.    54 to less than 57     7
  118.    54 to less than 57     8
  119.    54 to less than 57     9 
  120.    54 to less than 57    10
  121.    54 to less than 57    11
  122.    54 to less than 57    12
  123.    54 to less than 57    13
  124.    54 to less than 57    14
  125.    54 to less than 57    15
  126.    54 to less than 57    16
  127.    54 to less than 57    17
  128.    54 to less than 57    18
  129.    54 to less than 57    19
  130.    54 to less than 57    20+
  131.    57 to less than 60    -5
  132.    57 to less than 60     6
  133.    57 to less than 60     7
  134.    57 to less than 60     8
  135.    57 to less than 60     9
  136.    57 to less than 60    10
  137.    57 to less than 60    11
  138.       57 to less than 60                12
  139.       57 to less than 60                13
  140.       57 to less than 60                14
  141.       57 to less than 60                15
  142.       57 to less than 60                16

<PAGE>
                                       31
                                   -continued

----------------------------------------------------
  No.           Hunter L                   Hunter b
----------------------------------------------------
143.         57 to less than 60                17
144.         57 to less than 60                18
145.         57 to less than 60                19
146.         57 to less than 60                20+
147.         60 to less than 63                -5 
148.         60 to less than 63                 6 
149.         60 to less than 63                 7
150.         60 to less than 63                 8
151.         60 to less than 63                 9
152.         60 to less than 63                10
153.         60 to less than 63                11
154.         60 to less than 63                12
155.         60 to less than 63                13
156.         60 to less than 63                14
157.         60 to less than 63                15
158.         60 to less than 63                16
159.         60 to less than 63                17
160.         60 to less than 63                18
161.         60 to less than 63                19
162.         60 to less than 63                20+
163.         63 to less than 66                -5
164.         63 to less than 66                 6
165.         63 to less than 66                 7
166.         63 to less than 66                 8
167.         63 to less than 66                 9
168.         63 to less than 66                10
169.         63 to less than 66                11
170.         63 to less than 66                12
171.         63 to less than 66                13
172.         63 to less than 66                14
173.         63 to less than 66                15
174.         63 to less than 66                16
175.         63 to less than 66                17
176.         63 to less than 66                18
177.         63 to less than 66                19
178.         63 to less than 66                20+
179.         66 to less than 69                -5
180.         66 to less than 69                 6
181.         66 to less than 69                 7
182.         66 to less than 69                 8
183.         66 to less than 69                 9
184.         66 to less than 69                10
185.         66 to less than 69                11
186.         66 to less than 69                12
187.         66 to less than 69                13
188.         66 to less than 69                14
189.         66 to less than 69                15
190.         66 to less than 69                16
191.         66 to less than 69                17
192.         66 to less than 69                18
193.         66 to less than 69                19
194.         66 to less than 69                20+ 
195.     greater than or equal to 69           -5
196.     greater than or equal to 69            6
197.     greater than or equal to 69            7
198.     greater than or equal to 69            8
199.     greater than or equal to 69            9
200.     greater than or equal to 69           10
201.     greater than or equal to 69           11
202.     greater than or equal to 69           12
203.     greater than or equal to 69           13
204.     greater than or equal to 69           14
205.     greater than or equal to 69           15
206.     greater than or equal to 69           16
207.     greater than or equal to 69           17
208.     greater than or equal to 69           18
209.     greater than or equal to 69           19
210.     greater than or equal to 69           20+
--------------------------------------------------------

Wherein the designation -5 means less than 5 but more than 4 and the designation
+12 means more than 12 but less than 13.

     62. The process according to claim 61 wherein the process for determining
a color characteristic comprises a process for determining a color
characteristic in a biological test subject.

<PAGE>
                                      32

     63. The process according to claim 61 wherein the process for determining
a color characteristic comprises a process for determining a color
characteristic in a biological test subject that is a human or animal test
subject.

     64. In a process for determining a color characteristic, the improvement
comprising the steps of:

     (a)  compiling a group of lightness measure color factor value ranges,
          said lightness measure color factor comprising a color factor whose
          value is substantially that of Hunter L, and

     (b)  associating with each lightness measure color factor value range a
          value of at least one further color factor for use in comparison with
          a measurement of the value of that at least one further color factor
          in the coloration of a test subject having a lightness measure color
          factor value in a corresponding range, said at least one further
          color factor comprising a color factor whose value is substantially
          that of color factor Hunter a, and the relationship between said
          lightness measure color factor value ranges and said associated color
          factor values being substantially as follows:

-------------------------------------------------------------------------------
               Hunter L                Hunter a
-------------------------------------------------------------------------------
     24 (or less) to 44                 4 to 16
               45 to 54                 4 to 18
               55 to 59                 5 to 25
               60 to 71 (or more)       6 to 30.
-------------------------------------------------------------------------------

     65. In a process for determining a color characteristic, the improvement
comprising the steps of:

     (a)  compiling a group of lightness measure color factor value ranges,
          said ranges comprising at least one range of a color factor whose
          value is substantially that of color factor Hunter L, said at least
          one range being selected from the ranges substantially as follows:

     Hunter L = less than 27, 27 to less than 30, 30 to less than 33, 33 to
     less than 36, 36 to less than 39, 39 to less than 42, 42 to less than 45,
     45 to less than 48, 48 to less than 51, 51 to less than 54, 54 to less
     than 57, 57 to less than 60, 60 to less than 63, 63 to less than 66, 66 to
     less than 69, and less than or equal to 69, and

     (b)  associating with each lightness measure color factor value range a
          value of a color factor for use in comparison with a measurement of
          the value of that color factor in the coloration of a test subject
          having a lightness measure color factor value within said range.

     66. A process of evaluating a test subject based on the coloration of said
test subject, the process comprising the steps of:

     (a)  measuring with a color measuring instrument a value of at first color
          factor in said test subject's coloration, said first color factor
          being dependent on the lightness of the coloration of said test
          subject; and

     (b)  measuring with a color measuring instrument a value of at least one
          further color factor in said test subject's coloration, said further
          color factor being dependent on the relative content of opponent
          colors in the coloration of said test subject;

     wherein at least one of steps (a) and (b) comprises arriving at a value
          of said color factor that correlates to a measure of coloration
          having established laboratory utility.

     67. The process according to claim 66, further comprising the step of
comparing the measured values of said first color factor and said at least one
further color factor with a range of values of said color factors that are
found in the colora-

<PAGE>
                                  5,671,735

                                      33

tions of subjects other than said test subject, to determine where within
said range the measured values of said color factors lie.

   68. The process according to either of claims 66 or 67, wherein the test
subject is selected from the group consisting of skin, tissue, excretions,
bodily fluids, hair and teeth.

   69. The process according to either of claims 66 or 67, wherein step (b)
comprises measuring the value of at least one further color factor that is
dependent on relative content of blue and yellow in said coloration.

   70. The process according to either of claims 66 or 67, wherein step (b)
comprises measuring the value of at least one further color factor that is
dependent on relative content of red and green in said coloration.

   71. The process according to either of claims 66 or 67, wherein each of steps
(a) and (b) comprises measuring the values of said first color factor and said
at least one further color factor at different locations on the test subject.

   72. The process according to either of claims 66 or 67, wherein each of steps
(a) and (b) comprises making a set of multiple measurements of the values of
each of said first color factor and said at least one further color factor and
averaging each set of multiple measurements.

   73. In a process for evaluating the coloration of a test subject, the
improvement comprising the steps of:

   (a) compiling a group of lightness measure color factor value ranges, said
       lightness measure color factor comprising a color factor whose value is
       substantially that of color factor Hunter L; and

   (b) associating with each lightness measure color factor value range a value
       of at least one further color factor for use in comparison with a
       measurement of the value of that color factor in the coloration of a test
       subject having a lightness measure color value in said range, said at
       least one further color factor comprising a color factor whose value is
       substantially that of at least one of color factors Hunter b and Hunter
       a, and the relationship between said lightness measure color factor value
       ranges and said associated color factor values being substantially as
       follows:

--------------------------------------------------------------------------------
CATEGORY                        L                 a                  b
                          -------------     -------------      -------------

NAME                       Min     Max       Min     Max        Min     Max
--------------------------------------------------------------------------------
Black                      0.00   14.00    -10.00    3.00     -10.00    5.00
Darkest Dark              14.00   16.00    -10.00    3.00     -10.00    1.00
Brown
Darkest Dark              14.00   16.00    -10.00    3.00       1.00    1.15
Brown
Darkest Dark              14.00   16.00    -10.00    3.00       1.15    1.25
Brown
Darkest Dark              14.00   16.00    -10.00    3.00       1.25    3.00
Brown
Darker Dark               16.00   19.00    -10.00    3.00     -10.00    2.70
Brown
Darker Dark               16.00   19.00    -10.00    3.00       2.70    2.95
Brown
Darker Dark               16.00   19.00    -10.00    3.00       2.95    3.20
Brown
Darker Dark               16.00   19.00    -10.00    3.00       3.20   10.00
Brown
Darker Dark               16.00   19.00      2.00    3.00     -10.00    2.70
Brown
(Cool Auburn Tones)
Darker Dark               16.00   19.00      2.00    3.00       3.20   10.00
Brown
(Warm Auburn Tones)

<PAGE>
                                      34
                                  -continued

-------------------------------------------------------------------------------
CATEGORY                            L               a                  b
                            ---------------    -------------  -----------------
NAME                          Min      Max      Min      Max     Min      Max
-------------------------------------------------------------------------------
Brown                        19.00    22.00    0.00     6.00   -10.00     2.95
Brown                        19.00    22.00    0.00     6.00     2.95     3.20
Brown                        19.00    22.00    0.00     6.00     3.20     3.45
Brown                        19.00    22.00    0.00     6.00     3.45    10.00
Brown                        19.00    22.00    3.50     6.00     3.45    10.00
(Warm Auburn
Tones)
Brown                        19.00    22.00    3.50     6.00   -10.00     3.45
(Cool Auburn
Tones)
Medium Brown                 22.00    27.00    1.00     6.00   -10.00     3.75
Medium Brown                 22.00    27.00    1.00     6.00     3.75     4.00
Golden Med                   22.00    27.00    1.00     6.00     4.00     4.25
Brown
Golden Med                   22.00    27.00    1.00     6.00     4.25    10.00
Brown
Medium Brown                 22.00    27.00    3.50     6.00     4.25    10.00
(Warm Auburn
Tones)
Medium Brown                 22.00    27.00    3.50     6.00   -10.00     4.25
(Cool Auburn
Tones)
Darkest Med                  27.00    28.00    1.80     6.00    -5.00     6.00
Blonde
Darkest Med                  27.00    28.00    1.80     5.00     6.00     6.50
Blonde
Darkest Med                  27.00    28.00    5.00     6.00     6.00     6.50
Blonde
Darkest Med                  27.00    28.00    1.80     6.00     6.50    15.00
Blonde
Medium Blonde                28.00    31.00    1.80     6.00    -5.00     6.00
Medium Blonde                28.00    31.00    1.80     5.00     6.00     6.50
Med. Golden                  28.00    31.00    5.00     6.00     6.00     6.50
Blonde
Med. Golden                  28.00    31.00    1.80     6.00     6.50    15.00
Blonde
Lightest Med                 31.00    33.00    1.80     6.00    -5.00     6.00
Blonde
Lightest Med                 31.00    33.00    1.80     5.00     6.00     6.50
Blonde
Lightest Med                 31.00    33.00    5.00     6.00     6.00     6.50
Blonde
Lightest Med                 31.00    33.00    1.80     6.00     6.50    15.00
Blonde
Light Blonde                 33.00    36.00    1.80     6.00    -5.00     7.00
Light Blonde                 33.00    36.00    1.80     5.00     7.00     7.50
Light Blonde                 33.00    36.00    5.00     6.00     7.00     7.50
Light Blonde                 33.00    36.00    1.80     6.00     7.50    20.00
Lighter Blonde               36.00    40.00    1.80     6.00    -5.00     8.00
Lighter Blonde               36.00    40.00    1.80     5.00     8.00     8.50
Lighter Blonde               36.00    40.00    5.00     6.00     8.00     8.50
Lighter Blonde               36.00    40.00    1.80     6.00     8.50    20.00
Lightest Blonde              40.00    80.00    1.80     7.00    -5.00     9.00
Lightest Blonde              40.00    80.00    1.80     5.00     9.00    10.00
Lightest Blonde              40.00    80.00    5.00     7.00     9.00    10.00
Lightest Blonde              40.00    80.00    1.80     7.00    10.00    30.00
Light Red                    22.00    28.00    6.00    30.00    -5.00     3.50
Light Red                    22.00    28.00    6.00    30.00     3.50     3.75
Light Red                    22.00    28.00    6.00    30.00     3.75     4.00
Light Red                    22.00    28.00    6.00    30.00     4.00    30.00
Medium Red                   19.00    22.00    6.00    30.00   -10.00     3.50
Medium Red                   19.00    22.00    6.00    30.00     3.50     3.75
Med Golden Red               19.00    22.00    6.00    30.00     3.75     4.00
Med Golden Red               19.00    22.00    6.00    30.00     4.00    30.00
Dark Red                     14.00    19.99    3.00    30.00   -10.00     2.50
Dark Red                     14.00    19.99    3.00    30.00     2.50     2.75
Dark Red                     14.00    19.99    3.00    30.00     2.75     3.00
Dark Red                     14.00    19.99    3.00    30.00     3.00    30.00
Red Blonde                   27.00    40.00    6.00    30.00     6.00    30.00
Red Blonde                   40.00    80.00    7.00    30.00     6.00    30.00

<PAGE>
                                  5,671,735

                                      35
                                  -continued

-------------------------------------------------------------------------------
CATEGORY                            L               a                  b
                            ---------------    -------------  -----------------
NAME                          Min      Max      Min      Max     Min      Max
-------------------------------------------------------------------------------

Black/Dk                     27.00    50.00  -10.00     1.80   -10.00     3.75
Brown/Med
Brown/Brown
w/
70%-90% Grey                 
Black/Dk                     27.00    50.00  -10.00     1.80     3.75     4.00
Brown/Med
Brown/Brown
w/
70%-90% Grey                 
Black/Dk                     27.00    50.00  -10.00     1.80     4.00     4.25
Brown/Med
Brown/Brown
w/
70%-90% Grey                 
Black/Dk                     27.00    50.00  -10.00     1.80     4.25    10.00
Brown/Med
Brown/Brown
w/
70%-90% Grey                 
Black/Dk                     23.00    27.00  -10.00     1.00   -10.00     3.75
Brown/Med
Brown/Brown
w/
40%-60% Grey                 
Black/Dk                     23.00    27.00  -10.00     1.00     3.75     4.00
Brown/Med
Brown/Brown
w/
40%-60% Grey                 
Black/Dk                     23.00    27.00  -10.00     1.00     4.00     4.25
Brown/Med
Brown/Brown
w/
40%-60% Grey                 
Black/Dk                     23.00    27.00  -10.00     1.00     4.25    10.00
Brown/Med
Brown/Brown
w/
40%-60% Grey

<PAGE>
                                      36
                                  -continued

-------------------------------------------------------------------------------
CATEGORY                            L               a                  b
                            ---------------    -------------  -----------------
NAME                          Min      Max      Min      Max     Min      Max
-------------------------------------------------------------------------------

                                For Grey Hair
                                --------------

Light Brown/Darkest Blonde
---------------------------

40%-60% Grey                  4.00    10.00  -10.00     -0.8
70%-90% Grey                 10.00      To   -10.00     -0.8

                                   Maximum
Dark Red, Medium Red or Medium Light Red 
----------------------------------------
40%-60% Grey                  6.00    10.00  -10.00    -0.80
70%-90% Grey                 10.00      To   -10.00    -0.80

                                   Maximum
Light Red or Red Blonde
------------------------
40%-60% Grey                  5.00     7.00  -10.00    -0.80
70%-90% Grey                  7.00      To   -10.00    -0.80

                                   Maximum
Medium to Medium Dark Blonde 
-----------------------------
40%-60% grey                  1.70     4.00    0.00     0.00
70%-90% Grey                  4.00      To     0.00     0.00

                                   Maximum
Light Blonde Hair 
-----------------
40%-60% Grey                -99.99    -0.25   -1.75    -1.25
70%-90% Grey                -99.99    -0.25  -99.99    -1.75

--------------------------------------------------------------------------------

Wherein negative values denote values less than zero.

74. The process according to claim 73 wherein step (a) comprises
assembling the group of lightness measure color factor value ranges in
machine-readable, tangible form and step (b) comprises associating said
at least one further color factor value with each lightness measure color
factor value range in said machine-readable, tangible form.

                                  * * * * *