A fuzzy set theoretical approach for color specification using color names

A fuzzy system which expresses vague colors in words (usually adjectives) is considered. The words (or color names) consist of a hue name with its modifier or only a hue name. This system can translate from input data in the hue system to color names (as the output). Triangular membership functions are applied to the hue angle, and conical membership functions are applied to the relationship between the lightness and the saturation. By regarding the membership function of tone modifier as a fuzzy relation between the lightness and the saturation, we can easily obtain a membership grade of the target modifier as output fuzzy set from projection of an input fuzzy set. Vague colors are indicated by about three modifiers with each grade. For a known hue name (e.g., red) the fuzzy system which can find out a few tone modifiers (e.g., dark, dull, deep, etc.) suitable for color names in common use is proposed.