1. Introduction

Hardly a day goes by without the need for each of us to verbally describe at least one color. The degree to which the other person understands our description depends on a number of factors. Did I use the common language of the street? Are we from the same geographic area? Do we both work in the same trade or occupation? Are we of the same ethnic group? How accurately must the color description be understood?

If we are discussing the physical attributes of the "redhead" that just walked by, the accuracy of color description is relatively unimportant. However, if we are discussing the color of the carpet to be installed in a large office building involving a considerable amount of money, then the color description as well as the lighting and viewing conditions under which the description applies must be very carefully specified and controlled.

If we allow ourselves to dream about an ideal color language, it must be able to:

1) Be understood by the public at least in a general way;

2) Describe a color with different degrees of

accuracy;

3) Use color names or numeral and/or letter designations interchangeably;

4) Specify color tolerances around a standard color:

5) Describe the color in terms of the best known color-order systems or collections of color samples; 6) Describe colors with the even greater accuracies that will be demanded in the future;

7) Correlate visual descriptions with instrumental measurements of a color; and

8) Provide meaningful translation of exotic or promotional color names.

A color language which is designed to meet these requirements will be described and its development and applications will be discussed.

2. Method of Color Designation

The Inter-Society Color Council (ISCC) [25]1

and the National Bureau of Standards (NBS) cooperated for many years in the development of the ISCC-NBS Method of Designating Colors and a Dictionary of Color Names, usually shortened to the Color Names Distionary (CND)2 [18, 23]. This publication describes the selection of the ISCC-NBS hue names and modifiers descriptive of the lightness and saturation of a color [sec. 4.2 and 5, CND] which form the basis of the ISCC-NBS Method. This publication also describes the method by which the psychological color solid3 [sec. 4.1, CND; 37-fig. 1], dimensioned according to the Munsell (fig. 2) scales of hue (red, yellow, purple-fig. 3), value (lightness-light, dark, very dark-fig. 4) and chroma (saturation-grayish, strong, vivid-fig. 5) [sec. 4, CND; 3, 29, 30, 42], is divided into 267 blocks. To each of these blocks is assigned the appropriate ISCC-NBS color name. The hue, value and chroma boundaries of each color-name block were adjusted so that the color ranges embodied in each color-name block reflected common usage of that ISCC-NBS color name [sec. 5, CND], figure 6. These 267 color-name blocks are described in 31 colorname charts [sec. 13, CND]. Thus it is possible, given the Munsell notation of a color, to determine the ISCC-NBS color name most descriptive of this color by assigning to it the color name of the color-name block in which this Munsell notation plots.

Figures in brackets [ ] indicate the literature references at the end of this paper (sec. 13).

The Color Names Dictionary [ref. 23] is frequently referenced in this paper. The abbreviation CND will be used to cite this source.

3 Such a color solid is a very convenient way to arrange and thereby to visualize colors according to their hue, value or lightness and chroma or saturation. Any non-fluorescent or non-retroreflective surface color. for instance, can be represented by a point in the color solid at its proper hue, value and chroma.

All Munsell notations determined from the Munsell Book of Color up to and including the 1929 Edition, were called Munsell Book notations. After the publication in 1943 of the OSA study of the Spacing of the Munsell Colors, all Munsell notations determined on the basis of the respaced colors in the 1943 Report were called Munsell renotations. This was to distinguish them from Munsell Book notations. After all Munsell colors were brought into conformity with the 1943 Report, and after sufficient years had lapsed that the term Munsell renotation had become of academic interest only, the term Munsell renotation has been replaced by Munsell notation.