Page:Atlas of the Munsell color system.djvu/15



CHART

RED AND BLUE-GREEN CHART. This chart presents a vertical plane passed through the axis of the color solid and bearing the complementary hues, red and blue-green. This pair of opposite hues is shown in regular measured scales from black to white, and from greyness to the strong- est color made in stable pigment.

VALUES of red and blue-green range vertically from black (0) to white (10). CHROMAS or strengths of color range horizontally from neutral gray to the maximum (10).

Each step in these color scales bears an appropriate symbol describing its light and its strength. Thus $R 4⁄10$ is vermilion, the standard red of the system, which exhibits 100% of chromatic strength and reflects 40% of the incident light. Its opposite $BG 4⁄5$ reflects the same percentage of light but only 50% of chroma. To balance this pair the areas must be inversely as the chroma, i. e., since blue-green is but half as strong as vermilion red, twice as much is required for a balance. Attention to these measures leads to pleasing combinations.

Any chosen steps of red and blue-green upon this chart may be balanced by noting their symbols:- thus light blue-green (BG|8|3) balances dark red ($R 2⁄3$) when the areas are inversely as the product of the symbols viz:-six parts of light blue-green and twenty- four parts of dark red.

Chapters III and IV of the handbook, "A Color notation" describe these balances and their combinations with other hues.

The symbol on each color step is its NAME, a measure of its light and strength by which it is to be memorized, written and reproduced.

AVOID DUST, HANDLING AND EXPOSURE TO STRONG LIGHT.