Red, yellow, blue, white and black are added in different proportions, and the effect is different. Red+yellow = orange, red+blue = purple, yellow+blue = green. Adding white will make the color lighter, adding black will make the color darker, and matching two colors with similar colors will make the color brighter. For example, when green yellow and green blue are matched, the green color is much more than purple blue and oblique. It should be noted that, generally speaking, the color adjusted by collocation is not as bright as the existing green, and so are other colors.