I do a lot of color theory when I paint human figures. When painting skin tones, You want to use different amounts of the primary colors: red, blue and yellow. All human skin has different amounts of each of those colors in it—for example, someone might have a more red toned face than someone who has a blue toned face. You can also use different browns, such as warm browns—which have more of a red or yellow hue, or cool browns, which have a more blue hue.
The School of Athens represents all the greatest mathematicians, philosophers and scientists from classical antiquity gathered together sharing their ideas and learning from each other. These figures all lived at different times, but here they are gathered together under one roof.