The document discusses color saturation and different saturation levels. It explains that saturation levels range from prismatic colors on the outer edge of the color wheel being most saturated to muted colors in the center being least saturated. Specific saturation levels are named including prismatic, muted, and chromatic grays. Examples of saturation gradients are provided showing the infinite number of colors that exist between two saturated colors and how achromatic grays are not directly on top of each other in a smooth gradient. The importance of paying attention to value differences in saturation studies is emphasized.