The present study considers a fuzzy color system in which three membership functions are constructed on a color triangle (or tone triangle). For a given fuzzy input, this system outputs the center of gravity of three weights that are associated with respective grades. Three fuzzy sets (red, green, and blue) are applied to the color triangle (or tone triangle) relationship. By evaluating the attributes of redness, greenness, and blueness, a target color can be easily obtained as the center of gravity of the resulting fuzzy set. The output of the system is a tone triangle, which includes a compound vector with three weights (scalars) in color space. The relationship between vagueness and possibility is shown by the input-output characteristic between the redness of the input and the chromaticness of the output.