In disk combinations when a pure color is combined with both a white and black disk the result will be a broken color. When a color is mixed with both black and white, i. e., with gray, and becomes thereby a broken color, it then belongs to a broken scale and educationally has no place in any pure scale, i. e., a scale in which the key tone is a pure color. Neither has a broken scale of a color any place in a chart of pure scales or spectrum scales.
Neutral Colors.—A term often improperly applied to grays, white, black, silver and gold. See passive colors.
Passive Colors.—A term suggested as covering black, white, silver, gold and very gray colors. The term "neutral colors" is often used in this sense but this is evidently improper if we are to confine the term "neutral gray" to the representation of white in shadow because as soon as a gray has any color in it, it is no longer neutral.
Active Colors.—Those colors neither passive or neutral. Necessarily both the terms "active" and "passive" used in relation to colors must be quite indefinite.
Complementary Colors.—As white light is the sum of all color if we take from white light a given color the remaining color is the complement of the given color. When the eye has been fatigued by looking intently for a few seconds at a red spot on a white wall and is then slightly turned to the wall, a faint tint of a bluish green is seen, and this is called the accidental color of the red, and . is supposed to be identical with its complementary color. If with the disks we determine a color which with a given color will produce by rotation a neutral gray, we have the complementary color more accurately than by any other means at present known in the use of pigmentary colors.
Harmony.—Two colors are said to be in harmony or to combine harmoniously if the effect is pleasing when they are in juxtaposition or are used in a composition.
Spectrum Circuit.—If a pigmentary imitation of the solar
