1. A color converting system including at least one processing device, the system comprising: a reflectance estimating unit that estimates spectral reflectances of an image in plural wavelength ranges, wherein one or more adjacent wavelength ranges of the plural wavelength ranges overlap; a reflectance synthesizing unit that synthesizes the estimated spectral reflectances into one spectral reflectance by removing a discontinuity of spectral reflectances within the one or more overlapping wavelength range; and a color converting unit, using the at least one processing device, that converts the image into a different color model based on the synthesized spectral reflectance, wherein each wavelength range includes a plurality of colors.