Nature is the source of all true color. In her harmonies are supreme beauty and artistry. Each flower's stem displays just the right match of greens. Each animal's fur sports its own sublime tonal gradations.

Margie Deeb, Beader’s Guide to Color

Changing the value, hue or intensity of a color can completely change our reaction to it. Too many unrelated colors will spoil the harmony. Pretty colors randomly placed often result in a chaotic look that won’t support the subject.

Margaret Kessler, Color Harmony in your Paintings