There is a nice distinction in the combination of primaries for the formation of secondaries, and exact proportions are quite necessary.
An orange, for instance, would be off shade if it did not consist of half red and half yellow, but in the making of the quaternaries, which are, at best, gray shades, exact proportions are not necessary.
Nevertheless, in [Diagram I] we have observed exact proportions in order to make our demonstration clear.
The harmony of analogy is the combination of colors related, but the relationship must be displayed in proportions consistent with the origin of each and every color used.
Let us assume that the prevailing note in a room, in either the side-wall or floor, is sage.
DIAGRAM IA
We can tell by drawing lines from the center of [Diagram I] to the extremities of the space marked sage that there is a little blue and a little yellow, some green and slate and citrine used in the composition of sage, and hence the use of these colors constitutes the harmony of relationship or analogy.
COLOR PROPORTIONS