Why are the three primary colors of color light red, green and blue?

The essence of determining the three primary colors of color and light is that they are independent, and none of them can be combined with the other two colors. In addition, the mixed color gamut of three primary colors is the largest, and other colors can be mixed by three primary colors in a certain proportion, and the number of colors obtained after mixing is the largest. In the process of color perception, the color of light source is related to three elements: light source, eyes and brain. Therefore, the selection of the three primary colors of color light involves the wavelength and energy of the light source, the spectral response interval of human eyes and other factors. From the energy point of view, color light mixing is the superposition of brightness, and the mixed color light must be brighter than each color light before mixing. Only the light with low brightness can be used as the primary color to mix more colors. Otherwise, if the light with high brightness is used as the primary color, their sum will be brighter, so the light with low brightness will never be mixed. At the same time, the three primary colors should be independent, and the three primary colors should not be concentrated in a certain region of the visible spectrum. Otherwise, not only the colors in other areas can't be mixed, but the selected primary color may be mixed with other two colors, losing its independence, not the real primary color. In the dispersion experiment of white light, we can observe that red, green and blue are evenly distributed in the whole visible spectrum, occupying a large area. If the prism is rotated properly to widen and narrow the spectrum, you will find that the area occupied by colored light has changed. In the narrowed spectrum, the colors of red (R), green (G) and blue (B) are the most prominent, while the colors of other colors gradually decline, and some colors have almost disappeared. The wavelength ranges of these three colors are: R(600~700nm), G(500~570nm) and B(400~470nm). In chromatics, the whole visible spectrum is generally divided into blue region, green region and red region for research. When red light, green light and blue light are mixed, yellow light, cyan light and magenta light can be obtained respectively. Magenta light does not exist in the spectrum, so we call it outrageous color. If we mix these three colors in equal proportion, we can get white light; By mixing these three colors in different proportions, different colors of light can be obtained. According to human visual physiological characteristics, there are three kinds of color-sensitive cone cells in human retina-red cells, green cells and blue cells, which are sensitive to red light, green light and blue light respectively. When one of the color-sensitive cells is strongly stimulated, it will cause the excitement of the color-sensitive cells and produce a feeling of color. The three color-sensitive cells of the human eye have the ability to combine colors. When a polychromatic light stimulates the human eye, the color-sensitive cells of the human eye can decompose it into three monochromatic lights: red, green and blue, and then mix them into one color. It is because of this TINT's ability that we can identify a wider range of colors except red, green and blue. To sum up, we can confirm that there are three basic colors of colored light, which are red, green and blue. These three kinds of colored light are not only the main colored light obtained by white light decomposition, but also the main components of mixed colored light, which can match the spectral response interval of human retinal cells and conform to the visual physiological effect of human eyes. These three colors are mixed in different proportions, and almost all colors in nature can be obtained, and the mixed color gamut is the largest; Moreover, these three colors are independent, and one primary color cannot be mixed with other primary colors. Therefore, we call red, green and blue the three primary colors of color light. In order to unify the understanding, CIE stipulated in 193 1 that the wavelengths of three primary colors are λ r = 700.0 nm, λ g = 546. 1 nm and λ b = 435.8 nm. In the study of chromatics, white light is often regarded as the synthesis of three primary colors: red, green and blue, in order to facilitate qualitative analysis. References:

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