In addition to emission and remission curves, color is also measured in terms of chroma, saturation, value, lightness, and brightness. Chroma, otherwise known as hue, refers simply to the color itself, in its most pure expression. Adding more of the same color may increase a color's intensity, but it does not alter its chroma. Black and white are called achromatic colors. It is the addition of one or the other of them to a particular color that determines the color saturation, which refers to the amount of pure color a chroma contains.
Value refers to the subtle difference between shades of colors and tints of colors.
If black is mixed with a particular chroma, the result is said to be a shade of the original color. If white is mixed with the same chroma, it is said to be tinted. Lightness and brightness do not refer to a specific component of color itself, but they help to describe color differences and put color in context. Lightness refers to the amount of light that is reflected from an object,and brightness refers to the luminance of an object in the context of its surroundings.