Rhythmic Harmony

"An artist, when he paints a tonal picture, has in mind the relative dark and light of colors, and their relative coolness and warmth. Let me explain. First the relative coolness or warmth of colors. The artist regards blue as the coolest hue. As a matter of fact violet reflects even less light than blue; still, for his practical purposes, an artist says that the cool hue is blue, and he associates with it violet and green. On the other hand, yellow, he treats as warm, and associates with it red and orange.

And, if you consider for a moment, the distinction of warm and cool hues, which is practiced by artists and founded on the nature of light, appeals to our own experience. You will have no hesitation in feeling that a bunch of violets, surrounded by green leaves, gives you a feeling of coolness, as compared with another bunch composed of red and yellow poppies.

Accordingly, if an artist has made up his mind that his tonal harmony shall be a cool one, he either composes it entirely of cool hues, or sees to it that some one or all of them shall ‘prevail.’ The warmer hues may be introduced for the sake of contrast, but very sparingly. And, of course, he will reverse his use of the hues, if he wishes the tone to be a warm one.

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When all is said and done, tone is the result of color relations,
so arranged that they produce a rhythmic harmony."

- Charles H. Caffin (1854 - 1918)
A Child's Guide to Pictures