Color cognition and categorization research often models the representation of color within and across individuals using specific cognitive constructs (e.g., individual's color category "best-exemplars", color processing "salience", etc.). I discuss the empirical validity of such constructs, some forms of evidence typically used to demonstrate color representations across individuals and groups of individuals, and the consequences of individual differences on such constructs. Results from empirical tests of individual color representation, color categorization, and simulated learning of color categories in individuals and populations are discussed.