Warm Colors.—Red, orange and yellow, and combinations in which they predominate.
Cool Colors.—Usually considered to be green, blue and violet, and the combinations in which they predominate. But it is, perhaps, questionable whether green and violet may properly be termed either warm or cool. The term cool as applied to colors is quite indefinite, except in a general way, but red, orange and yellow are universally considered as warm, and blue and green-blue as cool.
Neutral Gray.—White in shade or shadow. Pure black and white mixed by disk rotation. Black and white pigments mixed do not usually produce a neutral gray, but rather a blue gray.
Warm Gray.—A neutral gray with the admixture of a small quantity of red, orange or yellow.
Cool Gray.—A neutral gray with a small quantity of blue or green-blue.
Green Gray.—A neutral gray having combined with it a small quantity of green. As this color could hardly be classed with either warm or cool grays this fourth class of grays is suggested as helpful in giving definiteness to the more general color expressions.
Broken Colors.—Gray colors, often improperly called broken tints. For simplicity, a tint of a color is described as the pure color mixed with white and a shade as the color mixed with black, and the corresponding broken color is the same color mixed with both white and black or with neutral gray. A tint of a color thrown into a shadow or a shade of a color in bright sunlight gives a broken color. For various reasons a very large proportion of the colors in nature are broken. Broken colors are much easier to combine harmoniously than full colors, or even tints and shades.
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.