How to make a color sphere with pigments.
(102) The preceding chapters have built up an ideal color solid, in which every sensation of color finds its place and is clearly An image should appear at this position in the text. named by its degree of hue, value, and chroma.
It has been shown that the neutral centre of the system is a balancing point for all colors, that a line through this centre finds opposite colors which balance and complement each other; and we are now ready to make a practical application, carrying out these ideal relations of color as far as pigments will permit in a color sphere[1] (Fig. 16).
(103) The materials are quite simple. First a colorless globe, mounted so as to spin freely on its axis. Then a measured scale of value, specially devised for this purpose, obtained by the day-light photometer.[2] Next a set of carefully chosen pigments, whose reasonable permanence has been tested by long use, and which are prepared so that they will not glisten when spread on the surface of the globe, but give a uniformly mat surface. A glass palette, palette knife, and some fine brushes complete the list.
(104) Here is a list of the paints arranged in pairs to represent