Fig. 22 The Munsell color system. Object colors are specified on scales of hue, value, and chroma. The hue dimension is located on the circumference of the cylinder. Any vane on the model represents a particular hue. Beginning with 10 basic color names, designating each as having 10 steps or gradations to the next color (e.g., R through 10 R for basic red to the next named color), the system ends up with an array of 100 hues around the circle. These carry symbols corresponding to color names (red, yellow, green, blue, purple) with combination names for each adjacent color in the circle. The value dimension is indicated by moving up or down the cylinder for a given hue. (Colors aligned horizontally all have the same value.) The lightest expression of that color (highest value) is at the top of the cylinder while the darkest is at the bottom. The chroma dimension, which has to do with the degree of saturation of the color, is indicated by how far a particular hue is from the axis of the cylinder. (Colors aligned vertically all have the same chroma.) At the axis a particular color, such as red, would be completely desaturated and would look white or gray to the eye. For each step outward, the color becomes increasingly saturated. On the circumference, as far out from the axis as possible, the color would look as vivid as possible. Because of manufacturing difficulties in producing surface colors, not all hues can be produced with the same chroma, and the Munsell cylinder consequently begins to look like a tree. All steps within a scale are intended to represent equal visual scale intervals for a normal observer. (Model by All-Color Company, Inc.; reproduced with permission of Lorain Fawcett, President.)