Art Lesson: Color Theory. Learn a working knowledge of color theory, including: primary and secondary colors, complementary colors, warm and cool colors. Color Theory is a set of basic rules for mixing colors to achieve a desired result. Wyland Tip: many fish can see a fairly good range of color. In some cases it's not as good as what we humans see - but it's much better than cats and dogs. Scientists say that good color vision helps animals find food on the land or in the water.