1. A method of color characterization for a color input device, comprising: receiving a set of device dependent color values corresponding to a set of reference color values in a device independent color space; and generating a forward model that maps device dependent color values to color values in the device independent color space using a regression analysis that minimizes a color difference metric between the reference color values and the set of device dependent color values mapped through the forward model, wherein the color difference metric defines a non-linear regression analysis.