All other lines are the tertiary or quaternary colors.

If we have clearly in our minds the appearance of the normal red and yellow, and clearly in our minds the orange that is made up by combining the two, we ought to be able to fix in our imagination the colors that come midway between the red and the orange, or the colors that come nearer the red or nearer the orange. Let us assume we are to select colors in the harmony of contrast. Take a ruler and lay across the chart and the contrasting colors are always opposite; the direct contrast of red is green because green is composed of the other two primary colors, yellow and blue; the contrast of blue is orange because orange is a combination of the other two primaries, yellow and red; the contrast of yellow is violet, a combination of blue and red.

Now, to determine the niceties of distinction, let us take a red that is a little off shade, a little yellowish; one must determine in the mind’s eye about how much yellow there is in it and, to determine the true contrast, carry your line across from the point which you think is represented by the yellowish and you find that it is green with a little blue added, or bluish-green.

129. One must also determine the scale of color. The parallel circular lines on the chart designate four scales, or four grades, of each color, growing lighter by adding white, to the center; as you add more and more white the tint becomes more and more light. In determining contrast, be careful to stick to your scale. Contrasts, to be in harmony, must be colors of the same scale.

130. Harmony of analogy or relationship is clearly expressed in the chart. The family relations of red are the things which go with red. We may have a harmony of analogy in violet which includes the relations of red and blue. We must not attempt to carry the family relationship too far. There is a wide range of variety in these combinations of analogy because they may include not only all scales of each color from the darkest tones to the lightest tints but they include tertiaries and quaternaries.

Each man must establish his own standard, and by establishing it he forms unconsciously a very comprehensive understanding of color. It has never been possible to print a true colored chart because no two copies of the sheet off the press would be alike. A little more ink or a little less ink, or a little lighter or a little heavier impression, changes the values.

The chart illustrates contrasts of all of the primaries and secondary colors and the broken colors or hues. In the same way the tertiary or quaternary colors may be arranged, but for convenience we show the contrasts as follows:

Russet:
Tertiary,
32 parts Red, 16 parts Yellow, 16 parts Blue
31 parts Red, 16 parts Yellow, 17 parts Blue
30 parts Red, 16 parts Yellow, 18 parts Blue
29 parts Red, 16 parts Yellow, 19 parts Blue
28 parts Red, 16 parts Yellow, 20 parts Blue
27 parts Red, 16 parts Yellow, 21 parts Blue
26 parts Red, 16 parts Yellow, 22 parts Blue
25 parts Red, 16 parts Yellow, 23 parts Blue

Slate:
Tertiary,
32 parts Blue, 16 parts Red, 16 parts Yellow
31 parts Blue, 16 parts Red, 17 parts Yellow
30 parts Blue, 16 parts Red, 18 parts Yellow
29 parts Blue, 16 parts Red, 19 parts Yellow
28 parts Blue, 16 parts Red, 20 parts Yellow
27 parts Blue, 16 parts Red, 21 parts Yellow
26 parts Blue, 16 parts Red, 22 parts Yellow
25 parts Blue, 16 parts Red, 23 parts Yellow

Citrine:
Tertiary,
32 parts Yellow, 16 parts Blue, 16 parts Red
31 parts Yellow, 16 parts Blue, 17 parts Red
30 parts Yellow, 16 parts Blue, 18 parts Red
29 parts Yellow, 16 parts Blue, 19 parts Red
28 parts Yellow, 16 parts Blue, 20 parts Red
27 parts Yellow, 16 parts Blue, 21 parts Red
26 parts Yellow, 16 parts Blue, 22 parts Red
25 parts Yellow, 16 parts Blue, 23 parts Red