The color of the samples exposed to a degradation test is measured before and after the test using a colorimeter or spectrocolorimeter. The details vary from one test method to another.

Laboratory measuring instruments are often used in the industry to check the color of manufactured products compared to a color standard. Obtaining the following coordinates:
ΔL * = difference in lightness and darkness (+ = lighter, – = darker)

Δa * = difference in red and green (+ = redder, – = greener)

Δb * = difference in yellow and blue (+ = yellower, – = bluer)

ΔE * = total color difference (total color difference of the three coordinates)

Equipment: Portable Spectrophotometer, Model: MiniScan XE Plus, Hunter Lab.

Standards: ISO 105 -A02, FLTM BI 109-01, SAE J1545, VW 50190, among others.