ions, and not attempting to describe them by the
indefinite and varying colors of natural objects. The system now to be
considered portrays the three dimensions of color, and measures each by
an appropriate scale. It does not rest upon the whim of an individual,
but upon physical measurements made possible by special color apparatus.
The results may be tested by any one who comes to the problem with "a
clear mind, a good eye, and a fair supply of patience."

[Footnote 2: See color variables in Glossary.]

+Clear mental images make clear speech. Vague thoughts find vague
utterance.+

(4) The child gathers flowers, hoards colored beads, chases butterflies,
and begs for the gaudiest painted toys. At first his strong color
sensations are sufficiently described by the simple terms of red,
yellow, green, blue, and purple. But he soon sees that some are light,
while others are dark, and later comes to perceive that each hue has
many grayer degrees. Now, if he wants to describe a particular
red,--such as that of his faded cap,--he is not content to merely call
it red, since he is aware of other red objects which are very unlike it.
So he gropes for means to define this particular red; and, having no
standard of comparison,--no scale by which to estimate,--he hesitatingly
says it is a "sort of dull red."

(5) Thus early is he cramped by the poverty of color language. He has
never been given an appropriate word for this color quality, and has to
borrow one signifying the opposite of sharp, which belongs to edge tools
rather than to colors.

+Most color terms are borrowed from other senses.+

(6) When his older sister refers to the "tone" of her green dress, or
speaks of the "key of color" in a picture, he is naturally confused,
because tone and key are terms associated in his mind with music. It may
not be long before he will hear that "a color note has been pitched too
high," or that a certain artist "paints in a minor key." All these terms
lead to mixed and indefinite ideas, and leave him unequipped for the
clear expression of color qualities.

(7) Musical art is not so handicapped. It has an established scale with
measured intervals and definite terms. Likewise, coloristic art must
establish a scale, measure its intervals, and name its qualities in
unmistakable fashion.

+Color has three dimensions.+

(8) It may sound strange to say that color has three dimensions, but it
is easily proved by the fact that