Faith,evidence, coercion again

Primary quality theories of colour claim that colours are intrinsic, objective, mind-independent properties of external objects. However, a recent, empirically motivated argument seems to have convinced many that primary quality theories cannot be sustained. This argument, in outline, alleges that colours bear structural relations to each other that no primary qualities bear to each other, and therefore that colours cannot be primary qualities. I believe the argument in question has been misunderstood. In this paper I shall examine arguments based on the structural properties of the colours in order to discern what they do and do not show about primary quality theories of colour.