1. A color processing apparatus, comprising: a memory for storing a plurality of colorimetric value sets, each of which is associated with a type of spectral distribution and white point information; an obtaining section, arranged to obtain a type of spectral distribution and white point information of a viewing illuminant; a selector, operable to select a colorimetric value set corresponding to the type of spectral distribution of the viewing illuminant from the plurality of colorimetric value sets stored in the memory; and a calculator, arranged to convert the selected colorimetric value set into a converted colorimetric value set based on the white point information of the viewing illuminant and the white point information of an illuminant of the selected colorimetric value set; wherein, when color temperature of the illuminant of the selected colorimetric value set is not identical with that of the viewing illuminant, the calculator calculates a colorimetric values set under the viewing illuminant from the converted colorimetric value set based on the color temperature of the viewing illuminant and the color temperature of the illuminant of the selected colorimetric value set so as to output the colorimetric value set under the viewing illuminant, and wherein, when the color temperature of the illuminant of the selected colorimetric value set is identical with that of the viewing illuminant, the calculator outputs the selected colorimetric value set as the colorimetric value set under the viewing illuminant.