From ‘chromatic’(1603) meaning ‘of or belonging to colour or colours’(OED), this term is used to refer to the essentialist distinction between people on the basis of colour. It is sometimes used in conjunction with the term ‘genitalism’,a distinction between men and women based on the obvious biological difference between male and female. Both terms are employed to indicate the fallacy of making simplistic and stereotypical distinctions of race and gender and to suggest that the   range of difference within these categories is a matter of representation and discursive construction.

SOURCE: ASHCROFT, Bill et al. Post colonial studies : the key concepts. New York: Routledge, 2007. (link)