1. A system for determining a true color of an unknown color sample, the system comprising: a template card including a cut-out and a plurality of concentric rings around the cut-out, each of the concentric rings having offset gray scales modulated as a function of an angle of a polar coordinate, wherein there is a trigonometric relationship between the gray scales of the plurality of concentric rings; a RGB color processor configured to determine, in an image of the template card over the unknown color sample, a first radial cross-section of one of the concentric rings having an intensity that matches a determined average red color value of the image of the unknown color sample and to determine a true average red color value of the unknown color sample based on an intensity profile of the one of the concentric rings and a polar angle of the first radial cross-section; and an angular processor configured to determine the polar angle of the first radial cross-section.