Page:Atlas of the Munsell color system.djvu/29



CHART

CHART 40. SCALES OF HUE AND CHROMA, REFLECTING 40% OF THE INCIDENT LIGHT. This chart is a horizontal section through the color solid, similar to chart 50 except that all its colors reflect 10% less light. It will be noticed by comparison that this weakens the yellow field, while the field of purple-blue is greatly increased. Each of the ten hues exhibits its scale of chroma on a radius from the neutral center (N-) to the strongest color obtainable in stable pigment. Thus YR, Y and GY, extend only to the fifth or middle step of chroma, while the powerful PB projects nearly twice as far to $undefined⁄9$.

To balance the unequal chromas of any opposite pair, the areas must be proportioned to the symbols printed on the colors: thus nine parts of $Y 4⁄5$ balances five parts of $PB 4⁄9$. Each concentric circle traces equal steps of chroma through the ten hues, and the suggestions for making color sequences which appear on the other charts apply here also. See Chapters III and IV of "A Color Notation"

AVOID DUST, HANDLING AND LONG EXPOSURE TO THE LIGHT.