For each paper type, a plurality of two-dimensional excitation characteristics tables Ti are provided in one to one correspondence with a plurality of colors i. The excitation characteristics table Ti for each color i contains a plurality of sets of excitation-reflectance data Bi (.lamda..sub.0, .lamda.) in a two-dimensional matrix form, for a plurality of combinations of incident light wavelengths .lamda. and reflected light wavelengths .lamda..sub.0. The excitation-reflectance data Bi (.lamda..sub.0, .lamda.) indicates the ratio of the amount of the reflected light wavelength .lamda..sub.0 generated in response to incidence of the incident light wavelength .lamda., with respect to the amount of the incident light wavelength .lamda.. Using the two-dimensional excitation characteristics table Ti corresponding to the user's selected paper type and using the spectral radiation characteristics S(.lamda.) of the user's selected light source type, Equations (9)-(11) are calculated to create an output profile, and color conversion is performed by using the output profile.