10. In music it is an established fact that certain notes used in pleasing combination produce sounds we call harmonies. The moment that more than one note is struck, there is danger of discord, and when ten notes resound to the touch of the player, they must be the right notes, or they jar upon the sensibilities. In the use of color the same immutable law applies.

11. In Circle Diagram II the letters RV mean reddish violet, being a violet having more red than blue i

its composition. BV means bluish violet, being a violet having more blue than red in its composition. BG means bluish green, being a green having more blue than yellow in its composition. YG means yellow green, being a green having more yellow than blue in its composition. YO means yellowish orange, being an orange having more yellow than red in its composition. RO means reddish orange, being an orange having more red than yellow in its composition. Thus we may advance from red to yellow by graduations almost imperceptible, by the addition of yellow, to a reddish orange, and so on gradually to orange, continuing on to yellowish orange, finally revealing pure yellow.






12. The contrasting color at any stage may be determined by proceeding in a direct line across the circle: Red has for its contrasting color green; hence, reddish orange would have for its contrasting color a bluish green, for the simple reason that if red contrasts with green and orange contrasts with blue, the color between the red and the orange would contrast with the color between the green and the blue. Let us determine the contrasting color for crimson. Crimson is simply a red slightly tinged with blue. If red contrasts with green, a shade a little to the left of red slightly tinged with blue would contrast with a shade a little to the right of green slightly tinged with yellow. In other words, crimson, RV, would contrast with yellowish green, YG. Determine at what point of the circle any color that you have in mind will come, and the contrasting color would be immediately opposite.

13. The harmony of analogy consists of the harmony of related colors or tones of one color.

14. The harmony of contrast consists of colors in no way related. As an example of the harmony of analogy, we would mention red and orange, because both of these colors have ingredients in common, red being one of the two component parts of orange. As an example of the harmony of contrast, we suggest red and green, because there is nothing in common between the two, red being a primary color, and green a secondary, composed of the other two primaries, yellow and blue.

15. Green is called the complement of red. The complement of blue would be orange, because orange is formed by combining the remaining primaries, red and yellow; and the complement of yellow would be violet, because violet is composed of blue and red, the other primaries.

16. In Diagram II we have arranged at opposite points the primaries 1, the secondaries 2, the tertiaries 3, the quaternaries 4.

But Diagram III goes further into the subject.

It is easy to understand the composition of secondaries, but it is not so easy to know the tertiaries and quaternaries.