1. A system, comprising: an interface that receives a color defined by a first coordinate in a first Cyan, Magenta, Yellow, and Key black (CMYK) color space; a color management unit that converts the color to a second coordinate for a second CMYK color space, determines a location in a perceptual color space for each of the first coordinate and the second coordinate, identifies a distance between the locations in the perceptual color space, and reduces the distance in the perceptual color space between the two locations by iteratively revising the second coordinate in the second CMYK color space while holding the black level of the second coordinate constant.