1. Tertiary colors are combinations of primary and secondary colours. There are six tertiary colors; red-orange, yellow-orange, yellow-green, blue-green, blue-violet, and red-violet. An easy way to remember these names is to place the primary name before the other colour.
2. Aesthetics, also spelled esthetics, the philosophical study of beauty and taste. It is closely related to the philosophy of art, which is concerned with the nature of art and the concepts in terms of which individual works of art are interpreted and evaluated.