Black and white are harmonious colors, not colors.
The principle of color matching is as follows.
First, the three primary colors.
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. Chromatics calls these three independent colors three primary colors, namely red, yellow and blue.
The color we see in printing is actually the light reflected by the paper we see. For example, this combination is used to adjust colors when painting. Pigment absorbs light, not the superposition of light.
Second, three colors.
The three primary colors are the colors that any two primary colors are mixed in the same proportion, also called secondary colors, which form contrast colors and complementary colors with the three primary colors.
Because the human eye has three different color photoreceptors, the color space we see can usually be represented by three basic colors, which are called "three primary colors". Three colors are two of the three primary colors added and mixed in the same proportion.
Tricolor: Also called "secondary color". It is a mixture of three primary colors and two primary colors according to 1: 1 Red and yellow merge into orange; Yellow and blue blend into green; Red and blue mixed with purple, orange, green and purple are called "three colors". When blending, due to the different weights of primary colors, it can also produce rich indirect color changes, such as red orange, yellow orange, yellow green, blue green, blue purple, red purple and so on.
Mix yellow and blue, because yellow can absorb blue light and indigo light, and blue can absorb orange light and yellow light, so it only reflects green light, which is why yellow and blue form green.
Similarly, red plus yellow turns orange, and red plus blue turns purple.