A method for generating a color mapping for a printing apparatus is described. The printing apparatus includes a plurality of colorants including a first colorant configured to reflect radiation having a first set of wavelengths and a second colorant configured to absorb radiation having a second set of wavelengths and emit radiation having a third set of wavelengths. The method includes obtaining spectral characteristics for the plurality of colorants, computing a gamut of colors available to the printing apparatus and determining a color mapping from an input color space to an output color space.