The neurobiology of color perception has long been a subject of interest both in the scientific community and in popular culture. Color perception varies widely from individual to individual, though it is difficult to characterize and quantify those differences. The effects of color on the function of the nervous system other than those related to vision, such as its effects on emotion, also remain elusive despite ongoing research. In his book Shades of Grey, Jasper Fforde takes the complexities of color perception and stretches them to their extremes. The novel, set in a vague semi-apocalyptic future, is unique in that the society it depicts is built entirely around the differences in its individuals’ color perception. At first, this seems absurdly