1. A method of performing UCR/GCR (Undercolor Removal/Gray Color Replacement) in a digital printer comprising: generating a grid of device independent color sampled nodes by sampling a color mapping function mapping a device independent color space at a plurality of sampling points (i,j,k) in the device-independent color space; generating a color list for each sampled node, each color list including one or more sets of device dependent color component combinations meeting a threshold accuracy criteria for the respective sampled device independent color node; selecting an initial device dependent color component combination from each color list; assigning each selected initial device dependent color combination to it's corresponding node; linear filtering the mapping function using the assigned device dependent color combinations; performing color projection by selecting a device dependent color value for each sampling point (i,j,k) to minimize error in a device independent color space and to minimize curvature in the device independent to device dependent mapping function; and repeating the steps of linearly filtering and performing color projection for a predetermined number of times or until determining that interpolation error is less than a predetermined threshold.