1. Three Primary Colors of Pigments The three primary colors used for subtractive coloring are called the three primary colors of the colorants. These three primary colors should have properties in which the two primary colors cannot be produced regardless of the mixing ratio.
The three primary colors of pigment should be cyan, magenta, and yellow. Each of their colors should be able to subtract one-third of the white light and reflect or transmit two-thirds of the light. The magenta color magenta is often referred to as subtractive green, yellow is called minus blue, and cyan is called minus red. Because each color of subtractive primary colors is equivalent to the color of white light minus one spectral color, this name and the name of additive primary colors can all correspond.
2. Color subtractive method refers to the method of subtractive color mixing principle according to the yellow, magenta and cyan raw materials (such as pigments, inks). We added red transparent paper to the incandescent lamp, and the light was red, as if the red transparent paper had a white color, which was actually the opposite.
We know that only when the three kinds of color cells on the human retina receive the same amount of intense stimuli at the same time they have white sensation. White light is the compound of multiple shades, red transparent paper absorbs white light, and other shades only Red light gives a red feeling.
If a yellow filter is used in place of the red transparent paper, not only the red light but also the green light are emitted, so that the yellow and green cells on the retina are stimulated at the same time, resulting in a yellowish feeling. It can be said that white light subtracts blue light and leaves red and green light to produce a yellow sensation. The effect of subtracting one or more color lights from white light (or composite light) to obtain another color light is called the subtractive effect, that is, the color reduction method.
If the red, green, and blue filters are stacked on top of a white light source, no light passes through. Because the wavelength range of the light filtered by the three color filters is irrelevant, that is, no one filter can transmit the light transmitted by the other two filters. The same test was performed using cyan, magenta, and yellow filters, and the situation was different.
Because each color filter passes two-thirds of the color in the spectrum, other colors can be created if they overlap on the same light source. Any two color filters combined to subtract light through one of the three primary colors of light.
For example, a cyan filter subtracts red light from white light, and a magenta filter subtracts green light. When the two filters are stacked together and the yellow filter subtracts blue light, all lights are Subtracted.
The cyan, magenta, and yellow pigments are mixed in equal amounts, and the color condition is similar to that of the color filter.
For example, a cyan pigment and a yellow pigment are mixed to produce green, and an overlap of a love filter and a yellow filter also produces green.
The essence of subtractive coloring is the fact that pigments or other colored substances selectively absorb certain color light in the white light spectrum, resulting in the effect of subtracting certain color light from white light. The color to be observed by the human eye is the white light minus. The shade of light left after some shades of light. The subtracted color light and the remaining color light complement each other.
The subtractive method shows that white light is the source of color, and all colors are contained in white light.