In the tree dimensional graph called Color Space, we can assign an absolute value to any color using three independent variables: Lightness, Chroma, and Hue.

Lightness (also called "value" - Lightness is plotted vertically in the color spcae graph with the darkest color at the bottom, the lightest color at the top.

Chroma (also called Saturation) - A color that is very saturated or intense has a high chroma. As colors become more chromatic they move in a horizontal direction away from the center of the color space.

Hue - The basic color of an object, such a "red", "Yellow", "green". Hue is located around the perimeter of the color space.