Color gradation is a term used to describe the gradual transition from one color to another. It can be achieved through the use of four different terms: TINT, TONE, SHADE, and HUE. TINT is a color mixed with white, resulting in a lighter version of the original color. TONE is a color mixed with gray, resulting in a muted version of the original color. SHADE is a color mixed with black, resulting in a darker version of the original color. HUE is the purest form of a color, without any other colors added.