Today, the major manufacturers of artist's colors, and even of household paints, have chemists to check all qualities of their products. As a result, chemically created pigments are often more uniform in color and quality than natural ones. Mars colors are a notable case. Reliability, however, doesn't necessarily imply brilliance. If you want truly bright colors in reds and yellows, spend a few extra cents, and buy cadmium colors.
Manufacturers indicate the permanency of each color on the label or in their catalog lists.
In normal circumstances, even these colors are quite satisfactory. After all, paintings are normally intended to be displayed in the home, not outdoors. In our age, all fine art colors marked permanent are absolutely intermixable. They may be mixed with any color without fear of some adverse chemical reaction. Furthermore, each brand may be safely mixed with any other brand, whether the colors are manufactured in the United States or Europe.