Sections R1 to R3 attempt to take the sting out of hostile commentaries. Sections R4 to R5 engage Berlin and Kay and the World Color Survey to correct the record. Section R6 begins the formulation of a new theory of colour as an engineering project with a technological developmental trajectory. It is recommended that the colour space be abandoned.

Naturalistic experiments of color perception are critically evaluated. The review concludes that they fail to confirm a natural determination of color perception. Rather than demonstrating universal sensitivity to focal colors, the experiments actually yielded enormous cultural variation in response. This variation is interpreted as supporting a sociohistorical psychological explanation of color perception.