## 2 Materials and Methods
### Optical Scanning Analysis of CARG-Ms  
For image processing, a custom application in MATLAB v2022b (CWL from MathWorks, Natick, MA, USA) was used. The results consisted of chromatic parameters: CIE L*a*b and the browning index (Figures 3-6 and Figures S9-S12, and Table S6). The b*c chromatic parameter accommodates colors from blue (negative values) to yellow (positive values). L* is the lightness parameter and accommodates colors with dark (L* = 0) to intense (L = 100) hues. Figure 3: Example of optical images under transmitted light for the first empty sample (**left**), first sample prepared by method 1 (**middle**), and first sample prepared by method 2 (**right**). Figure 2: SEM analysis of microspheres with/without RG extract. Figures 3-6 show an image processing example for the transmittance light and reflective light scanning cases. Each input image was composed of empty microspheres, microspheres prepared by method 1, and microspheres prepared by method 2 (images correspond from left to right). Both scan cases show almost the same visual and browning index-coded results (Table S6). The empty sample (with the leftmost positioning) is rendered in grey levels and looks to be the most transparent. The browning index for the empty samples tested under reflective light ranged from 1.6 to 5.1, the b* chromatic values ranged from \(-1.17\) to 0.34, and the lightness of L* ranged from 23.8 to 28.2 (Table S1). In conclusion, these samples exhibited a transparent blue color. In the same way, the empty samples tested under transmittance light were a lighter transparent blue (browning index ranged from 4.9 to 7.9,  
Figure 4: Browning index (BI) pixel coding of transmittance scanned images for the first empty sample, the first sample prepared by method 1, and first sample prepared by method 2 (from left to right, corresponding to Figure 3). Figure 5: Reflective scanned images for the first empty sample (**left**), first sample prepared by method 1 (**middle**), and the first sample prepared by method 2 (**right**). Figure 6: Browning index (BI) pixel coding of reflective scanned images for the first empty sample, the first sample prepared by method 1, and the first sample prepared by method 2 (from left to right, corresponding to Figure 5). b* ranged from \(-\)0.51 to 0.02, and L* ranged from 28.2 to 38.4) than the empty samples tested under reflective light. The sample prepared by method 1 (with focused positioning) was rendered in yellow-brown hues and had less transparency than E1. The browning index for the samples prepared by method 1 tested under reflective light ranged from 21.1 to 27.5. The b* chromatic values ranged from 8.4 to 11.7 and the lightness L* ranged from 18.3 to 21.8. In conclusion, the microspheres that were prepared by method 1 and were tested in reflective light presented a matt brown ochre color. In the same way, the samples prepared by method 1 tested under transmittance light presented a yellow ochre color (browning index ranged from 24.8 to 31.6, b* ranged from 5.75 to 6.17, and L* ranged from 30.25 to 34.4). Therefore, it showed a lighter color than the same samples tested under reflective light. The sample prepared by method 2 (with rightmost positioning) was rendered in brown hues and had no transparency. The browning index for these samples under reflective light ranged from 62.6 to 66.5, the b* chromatic values ranged from 12.53 to 18.2, and the lightness L* ranged from 14.5 to 20.8. In conclusion, these samples presented a matt brown color. In the same way, under transmittance light, the samples presented a lighter brown ochre color (the browning index ranged from 50.4 to 55.6, b* ranged from 12.7 to 17.7, and L* ranged from 23.7 to 31.03) than the same samples tested under reflective light. Figures 3 and 6 visually prove the previous conclusion by coding the browning index values of the analyzed samples.