A: Primary color theory

Three primary colors, the so-called three primary colors, means that none of these three colors can be mixed with the other two primary colors, while other colors can be mixed with these three colors in a certain proportion. Chromaticity calls these three independent colors three primary colors.

B: color mixing theory

Color mixing can be divided into additive mixing and subtractive mixing, and colors can also be mixed after entering the vision, which is called neutral mixing.

Additive mixing

Additive mixing refers to the mixing of colored light. When more than two kinds of light are mixed together, the brightness will be improved, and the total brightness of the mixed colors is equal to the sum of the brightness of the mixed colors. In terms of color and light mixing, the three primary colors are vermilion, emerald green and blue purple. These three colors of light cannot be produced by mixing other colors of light. And:

Zhu Guang+Emerald Light = Yellow Light

Emerald light+blue violet light = blue light

Blue-purple light+vermilion light = purplish red light

Yellow light, blue light and purple light are intermediate colors.

If only two colors of light can be mixed to produce white light, then the two colors are complementary. For example: scarlet light and blue light; Emerald green light and purple light; Blue violet and yellow light.

(2) Subtractive mixing

Subtractive mixing mainly refers to the mixing of pigments.

After the white light passes through the color filter, part of the light is reflected to absorb the rest of the light, reducing part of the radiation power, and the finally transmitted light is the result of two light reductions. This color mixing is called subtractive color mixing. Generally speaking, dyes with strong transparency have obvious dimming effect after mixing.

Subtractive mixed three primary colors are the complementary colors of additive mixed three primary colors, that is, the complementary colors of green red (magenta), blue purple yellow (light yellow) and vermilion blue (sky blue). Mix two original tones to produce an intermediate color:

Red+blue = purple

Yellow+Red = Orange

Yellow+blue = green

If two colors can produce gray or black, these two colors are complementary colors. The three primary colors are mixed in a certain proportion, and the obtained color can be black or black-gray. In subtractive mixing, the more colors are mixed, the lower the brightness and the lower the purity.

(3) Neutral mixing

Neutral mixing is a kind of visual color mixing based on human visual physiological characteristics, which does not change the color light or the luminescent material itself, and the brightness of the color mixing effect neither increases nor decreases, so it is called neutral mixing.

There are two visual blending methods:

Answer: color rotation and mixing: put two or more colors side by side on a disk, and rotate hard and quickly to see the new color. The effect of color rotation mixing is similar to additive mixing in hue, but it is the average value of mixed colors in lightness.

B: Spatial mixing: When different colors are juxtaposed, when their projections on the retina are small to a certain extent, these different color stimuli will act on the photoreceptor cells in very adjacent parts of the retina at the same time, making it difficult for the eyes to distinguish independently, and color mixing will occur visually. This mixing is called spatial mixing.