Page:Atlas of the Munsell color system.djvu/35



CHART

CHART 70. LIGHT VALUE SCALES OF HUE AND CHROMA. This chart is a horizontal section through the color solid, similar to that of chart 50 except that all of its colors reflect 70% of the incident light.

Each radius is A SCALE OF CHROMA starting from the neutral center $N⁄7$. It traces a regular increase of strength in its pigment hue, and each step bears an appropriate symbol. Thus $R 7⁄6$ indicates that the red upon which it is placed reflects seven-tenths of standard white and six-tenths of standard vermilion.

Its opposite or complement, blue-green ($BG 7⁄5$) is slightly weaker at this level, as appears in the numeral 5 written below the line, and to balance this pair, six parts of blue green should be used with five parts of the red.

Each concentric circle traces hues of uniform chroma, the two inner circles being complete with ten STEPS OF HUE, which are written $R 7⁄2$, $YR 7⁄2$, $Y 7⁄2$, $GY 7⁄2$, $G 7⁄2$, $BG 7⁄2$, $B 7⁄2$ $PB 7⁄2$, $P 7⁄2$, $RP 7⁄2$, showing that both value and chroma are equal.

The third circle is incomplete for want of a purple-blue. In the fourth circle its neighbor purple is also missing. The fifth circle has no representatives from blue-green to red : in the sixth blue-green disappears : the seventh only presents green, yellow-green, yellow and yellow-red, while the eighth circle is represented by yellow alone.

These radii describe the unequal strength of pigments at this level of the color solid and should be contrasted with chart 30 where the relations of strength and weakness are reversed.

For a study of balances and sequences on this chart see Chapters III and IV of "A Color Notation" by the author.

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