a number) at the right, below the line. Thus R510 means hue (red), Value (5)CHROMA (10) and will be found to represent the qualities of the pigment vermilion.[1]
Hue, value, and chroma unite in every color sensation, but the child cannot grasp them all at once. Hue-difference appeals to him first, and he gains a permanent idea of five principal hues from the enamels of middle colors, learning to name, match, imitate, and finally write them by their initials: R (red), Y (yellow), G (green), B (blue), and P (purple). Intermediates formed by uniting successive pairs are also written by the joined initials, YR (yellow-red), GY (green-yellow), BG (blue-green), PB (purple-blue), and RP (red-purple).
(41) Ten differences of hue are as many as a child can render at the outset, yet in matching and imitating them he becomes aware of their light and dark quality, and learns to separate it from hue as value-difference. Middle colors, as implied by that name, stand midway between white and black,—that is, on the equator of the sphere,—so that a middle red will be written R3 , suggesting the steps 6, 7, 8, and 9 which are above the equator, while steps 4, 3, 2, and 1 are below. It is well to show only three values of a color at first; for instance, the middle value contrasted with a light and a dark one. These are written R3 , R5 , R7 . Soon he perceives and can imitate finer differences, and the red scale may be written entire, as R1 , R3 , R3 , R4 , R5 , R6 , R7 , R8 , R9 , with black as 0 and white as 10.
(42) Chroma-difference is the third and most subtle color quality. The child is already unconsciously familiar with the middle chroma of red, having had the enamels of middle color always
- ↑ See Chapter VI.
