Page:Atlas of the Munsell color system.djvu/19



CHART

GREEN AND RED-PURPLE CHART.

This chart presents a vertical plane passed through the axis of the color solid and bears the complementary hues, green and red-purple. This pair of opposite hues is shown in regular measured scales from black to white and from greyness to the strongest color made in stable pigment.

VALUES of green and red-purple 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 $G 5⁄7$ is emerald green, the strongest permanent green, which exhibits 70% of chromatic strength and reflects 50% of the incident light. Its opposite $RP 5⁄6$ reflects the same percentage of light but only 60% of chroma. To balance this pair the areas must be inversely as the chroma, i. e., since red-purple is one seventh less strong than green, seven parts of red-purple will balance six parts of the green, Attention to these measures leads to pleasing combinations.

Any chosen steps of green and red-purple upon this chart may be balanced by noting their symbols:, thus light green ($6 8⁄5$) balances dark red-purple ($RP 2⁄2$), when the areas are inversely as the product of the symbols viz:- forty parts of dark red-purple and four parts of light green. 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.