Atlas of the Munsell color system

Abstract

Imagine a colored sphere with white as its north pole, black as its south pole, and its equator ringed about by a circuit of red, yellow, green, blue and purple hues-each of which melts imperceptibly into its neighbors, Fig, 1 Thus the equator traces the horizontal scale of hues: H.Imagine each equatorial hue as graded upward to white and downward to black in regular measured steps.Each hue then presents a scale of values over the surface, while the axis traces the vertical scale of gray values: V.Imagine surface colors weakened by additions of neutral gray as they pass inward to disappear in the vertical axis.The sphere is thus filled with gradations of color,-lighter degrees above the equator, darker degrees below; stronger degrees outward, and weaker degrees inward to the axis, where all color is balanced in neutrality.Th'e degree of color strength at any point is known as chroma and is traced by radii at right angles to the axis.It represents the gradual emergence of each hue from grayness.Each radius serves as a scale of chromas: C.Every color sensation may be measured and defined by these three scales of hue , Value , and chroma.Neglect of either scale-that is, failure to state either the hue, the value, or the chroma of a color-creates doubt and confusion. A COLOR TREE SURROUNDS THE COLOR SPHERE.Were all pigment colors of equal chroma then a sphere would present an ideal of their relations.But pigments are very unequal in strength, Vermilion red,t for example, being twice as strong as its opposite complement, blue-green Viridian.This is shown in chart 40.The unequal scales of pigment chroma may be treated as branches of a Color Tree whose trunk is the neutral axis, while its branches of various lengths and at various levels blossom out with the strongest colors.This tree is imagined as compact of colored leaves-darker leaves below, lighter leaves above; most chromatic leaves on the surface and grayer leaves inward to the trunk, which is colorless.The tree also encloses the Color Sphere, which would appear were the longer branches lopped off to equal the length of the shortest branch.Fig. 2. 3. NOTATION OF COLORS BY SYEVEBOLS.The place of each leaf of the Color Tree is determined by the measured scales of hue, value and chroma.These scales also furnish an expressive notation, made by the five color initials with their combinations and ten arabic numbers.The scale of hue is a sequence of red (R), yellow-red (YR), yellow (Y), green-yellow (GY), green (G), blue-green (BG), blue (B), purple-blue (PB), purple (P), and red-purple (RP).