three only, Orange, Green and Purple. Each of these is composed of, and can be resolved into, two primaries; thus Orange is composed of Red and Yellow, Green of Yellow and Blue and Purple of Blue and Red.
Tertiary colors are three only, Citrine, Russet and Olive. Each of these is composed of, or can be resolved into, either two secondary colors or the three primaries; thus Citrine consists of Green and Orange, or of a predominant Yellow with Blue and Red; Russet is compounded of Orange and Purple, or of a predominant Red with Blue and Yellow, and Olive is composed of Purple and Green, or of a predominant Blue with Yellow and Red.
The last three genera of colors comprehend in an orderly gradation all those which are positive or definite, and the three colors of each genus, united or compounded in such subordination that neither of them predominates to the eye, constitute the negative or neutral colors of which black and white have been stated to be the opposed extremes, and grays their intermediates. Thus Black and White are constituted of, and comprise latently, the principles of all colors and accompany them in their depth and brilliancy, as shade and light.
Semi-neutral colors belong to a class of which Brown, Maroon and Gray may be considered types. They are so called because they comprehend all the combinations of the primary, secondary and tertiary colors with the neutral black. Of the various combinations of black, those in which yellow, orange or citrine predominates have obtained the name of brown; a second class, in which the compounds of black are of a predominant red, purple or russet hue, comprise maroon, chocolate; and a third class, in which the combinations of black have a predominant hue of blue, green or olive, include gray and slate.
It must be observed that each color may comprehend an infinite series of shades between the extremes of light and dark, as each compound color may comprise a series of
