1. A computer implemented method, comprising: receiving, with a spectrophotometer, spectral reflectance light reflected from a plurality of pigments present in a collection of coatings; generating, using a processor, a set of calibration data relating to the plurality of pigments that are present in the collection of coatings, wherein generating includes: converting at least a portion of the spectral reflectance light received by the spectrophotometer into spectral reflectance data; converting the measured spectral reflectance data to internal reflectance data for use with a color matching calculation by using Saunderson conversion, wherein at least one of Fresnel coefficients K1, K2, or a combination thereof is varied by angle, wavelength, and concentration to yield multiple sets of internal reflectance data; calculating multiple sets of absorption/reflectance data from the corresponding calculated multiple sets of internal reflectance data using a color matching calculation; calculating a plurality of concentrations of a non-standard pigment; plotting a relationship between the concentrations and the calculated absorption/reflectance data for each combination of K1 and K2 at a given angle and wavelength; fitting the plotted data to identify a set of absorption/reflectance data corresponding to a set of K1 and K2 values; and determining a correlation of the concentrations and each of the K1 and K2 values determined by the fitting of the plotted data; determining, using the processor, a coating formulation of a target coating based on the correlation; and creating a mixture in response to the determined coating formulation of the target coating.