Small samples of each color are made in a lab to measure consistency and lightfastness.
每种颜色的小样本在实验室中制作,以测量一致性和耐光性。
英语百科
Lightfastness
Lightfastness is a property of a pigment or paint that describes how resistant to fading it is when exposed to light. Light striking a painted surface can alter or break the chemical bonds of the pigment, causing the colors to bleach or change, in a process known as photodegradation. Materials that resist this effect are said to be lightfast.