The Complementaries
136. Considering the circuit of the colors which we are able to produce with our pigment-materials, the question arises, What contrasts of color are the strongest? what interval in the Scale of Colors gives us the strongest possible color-contrast? Producing the twelve colors in the values of their greatest intensities, and as intense as possible, and setting the tones in a circuit and in their natural and inevitable order, you will observe that the greatest color-contrast is the contrast between colors at the interval of the seventh: for example, the contrasts of Red and Green, or Orange and Blue, or Yellow and Violet. The colors at the interval of the sixth are less strong in contrast. The contrast diminishes gradually as we pass from the interval of the seventh to the interval of the second. The contrast of colors at the interval of the seventh, the greatest possible contrast, is called the contrast of the complementaries. In estimating intervals we count the colors between which the intervals occur.