A color conversion apparatus receives red-green-blue color data, calculates characteristic information and first hue region data from the color data, adjusts the first hue region data according to the characteristic information to obtain second to N-th hue region data, N being an integer equal to or greater than three, generates matrix coefficients for the second to N-th hue region data, and performs a matrix operation on the second to N-th hue region data to obtain color data with four or more color components. Color data with three primary components are thereby converted to color data with four or more primary components by simple calculations, without using a large amount of memory space.