How to grasp the three primary colors in post-production of photography

Three primary colors are usually divided into two categories, one is the three primary colors of color and light, the other is the three primary colors of pigment, but in art, red, yellow and blue are defined as the three primary colors of color. However, artistic practice has proved that adding a little yellow to magenta can adjust its size (=M 100+Y 100), but scarlet can't adjust magenta. Adding a little magenta to cyan can get blue (blue =C 100+M 100), and adding green to blue can get dull cyan. More colors can be mixed with yellow, magenta and cyan, which are pure and bright. Green mixed with green and yellow (green =Y 100+C 100) is purer and brighter than green mixed with blue and yellow, while the latter is darker. Magenta and blue are pure purple (purple =C20+M80), red and blue can only get gray purple and so on. In addition, from the perspective of integrating other colors, yellow, magenta and cyan are all their primary colors, with richer colors and purer and brighter colors.