Light refracted by pigments forms colors by light waves of different wavelengths. Light color can be decomposed into seven colors, which is not equal to paint color. The three primary colors of pigment color are magenta, lemon yellow and indigo. The three primary colors are black in theory, but in fact they turn gray because of insufficient purity. To understand color, we must understand the color circle, which explains what the same color, adjacent color and complementary color are, and we can also see the gradual change of color brightness from the relationship between black, white and gray. Black, white and gray are not colors, so they are not in the color circle.

Painting color is called "color" because it not only expresses the relationship between colors, but also expresses the relationship between black, white and gray. Color refers to black, white and gray, and color refers to red, yellow and blue.

The natural color and environmental color of light source color mentioned upstairs are commonly used conditional color concepts. Originated from impressionism and roving painting. But there is also an inherent color system in the concept of color, regardless of light source color, environmental color and so on. Like Matisse and China. Contemporary painting generally does not consider environmental color.

No matter what kind of concept, the color relationship is the same. Especially the color tone, cold and warm. How to understand the relationship? 1, the tone should be harmonious and there should be a little contrast. 2. If the relationship between the temperature and lightness of two things is 10:5, then you can draw the intensities of 6:3 and 2: 1 correctly. 3. In order to achieve harmony, the color of a place can be reduced or changed appropriately. In other words, we should deal with it subjectively according to our needs.