Page:Atlas of the Munsell color system.djvu/31



CHART

CHART 30. MIDDLE VALUE SCALES OF HUE AND CHROMA This Chart is a horizontal section through the center of the Color Solid, classifying all colors of MIDDLE VALUE by measured scales, of HUE and CHROMA.

Each radius is a SCALE OF CHROMA starting from the neutral center $N undefined⁄5$. It traces a regular increase in the chroma of its pigment hue, and bears appropriate symbols. Thus $R 5⁄9$ indicates that the red upon which it is placed reflects 50% of standard white and 90% of the strength of standard vermilion.

Each circle struck from the neutral center is a SCALE OF HUE. It is a circuit of ten measured hues, equal in value and chroma. This equality appears in their symbols, — $R 5⁄5$, $YR 5⁄5$, $Y 5⁄5$, $GY 5⁄5$, $G 5⁄5$, $BG 5⁄5$, $B 5⁄5$, $PB 5⁄5$, $P 5⁄5$ and $RP 5⁄5$, which is a balanced circle of hues reflecting 50% of standard white and 50% of the chroma of standard vermilion.

A BALANCE of opposite hues which complement and enhance one another, is obtained by equal areas of equal chroma : such as BG$5⁄5$, and $R 5⁄5$ — or by compensating areas of unequal chroma, such as nine parts of $BG 5⁄5$, with five parts of $R 5⁄9$.

A SEQUENCE of successive hues combined with increasing chroma in equal additions is traced thus: $B undefined⁄2$. $G undefined⁄4$. .$y undefined⁄6$. $R undefined⁄8$. or the differences may be doubled thus: $P undefined⁄1$. $G undefined⁄5$. $R⁄9$. In short, the qualitative and quantitative construction of this chart by measured intervals, insures an orderly succession of colors, and any selection, — regular or irregular, — is at once evident in the written symbols. See Chapters III and VI of "A COLOR NOTATION," by the author, which describes the nature and use of these charts.

AVOID HANDLING and EXPOSURE TO LIGHT or DUST.