1. A method for evaluating a color of a sample, comprising: acquiring a plurality of images of the sample, where each of the plurality of images is acquired under a different one of a first plurality of illuminants and each of the plurality of images contains a set of samples of known spectral reflectance; computing a single mapping that transforms all of first pluralities of values into second pluralities of values, wherein each plurality of values of the first pluralities of values comprises each red, green, and blue sensor value of each sample in the set of samples under each of the first plurality of illuminants, and each plurality of values of the second pluralities of values comprises each tristimulus X, Y, and Z reflectance value of each sample in the set of samples under each of a second plurality of illuminants; and color calibrating the plurality of images using the single mapping, wherein the color calibrating results in a plurality of color calibrated images each comprising a plurality of pixels.