Oil Painting 101: W. David Price
How to Mix Paint.
There are three elements to color:
Hue: Hues are blue, red, and yellow. Exact names such as Yellow Ocher refer to pigments, not hues.
Chroma: Chroma refers to intensity — how bright or how dull a color is. The intensity, or chroma, of a hue is dulled by adding a touch of the color found opposite from it on the color wheel. Example: By adding a touch of blue to red, the red becomes dull.
Value: Value refers to the lightness or darkness of color. Value can be adjusted by mixing a hue with black, white, yellow, yellow ochre, burnt umber, etc.