I believe value to be more important to the success of a painting than the actual color used. While we can key a painting’s value to use a limited part of the total value scale, we cannot manipulate values in the same way that we can manipulate color. All good paintings start with good value plans. This arrangement is what gives strength to your paintings.
The Value Scale
The value scale is the scale that we are limited to in pigment between black and white. While we can divide the scale into as many steps as we want, usually it is divided into ten steps or less. I divide this scale from 0 (black) to 9 (white).
A good value plan in a painting usually has four values. When creating a value plan it is better to let one value dominate. The other three values, in total, should make up an uneven division of space, less than the dominant value. With this plan it is a good idea to reserve two values for the light areas and two for the shadow areas. This would be a light and a light halftone and a dark and a dark halftone.
The amount of variety is infinite once you start modeling the large masses and manipulate edges to soften or harden shapes. Remember---the strength of a painting comes from its organization and a unifying idea. It is the way you manipulate reality to get that idea across. Value, more than color, helps you achieve this.