PS Amazing Examples: Carefully Pondering Human Skin Tone
Part One: Theoretical Section:
1. The first image shows the four basic colors used to paint Caucasian skin tones. These include one yellow, one red, and a cool color, which can be either green or blue. White is also necessary. If you are painting with a limited palette or a darker color scheme, black is included as well. However, I don't count black here because I want to ignore that color until we're truly ready to use it.
At the top of the example image, there is a blend of these four basic colors without shadow tones since we are not concerned with those at this moment. We only need the skin tone hues.
Half of the second example showcases intermediate tones achieved by adding red and yellow, and how they interact when mixed. You can experiment with any mixing intensity and try it out everywhere.
Using a rosy tone is a great idea for creating perfect skin tones. There's such a wide variety of skin tones—different people, different artistic images. For instance, if someone needs Drew Struzan to paint Harrison Ford's portrait, they would ask what style of depiction you prefer: one that emphasizes painterly qualities or one that seeks realism. This difference will tell you whether you should directly use the paint squeezed from the tube.
Red100 - The Story of the Red Photo Studio
http://www.vip-dm.cn/blog/