These are colors that can’t be created by mixing of other colors. Primary colors include yellow, blue, and red. Accurately combining colors, using the color wheel, and understanding how colors relate to each other are critical skills for artists, designers, marketers, and brand owners. Color theory is the art of combining colors based on the color wheel, an organized illustration of the primary, secondary, and tertiary colors. If you’re studying fine arts or design as part of a liberal arts degree program, it’s important for you to have a solid command of color theory.