Conversion from raw camera coordinates to a standard color space is developed here as a direct product of two independent maps, one for chromaticity coordinates of hue and saturation, the other for brightness. The principal focus is on the former. While the main approach is a target-based mapping, comparison with a more conventional approach shows that the structure of chromaticity for point reflection spectra at the capture gamut boundary influences the map far into the interior. Failure to account properly for this systematic effect is the largest source of error in standard color mappings. Restriction to chromatic mappings defines a class of corresponding chromatic metamers. Failure of a camera to satisfy the Luther condition produces two distinct classes of chromatic metamer errors: essential and adventitious.