MANIFESTO

An adequate theory of colour must be both materialistic and commensensical. The former demand is non-negotiable. The latter can be compromised to some degree. We need not be ‘ever so inclusive’ in advancing all our offhand folk-theoretical opinions as conditions of adequacy on a theory. Imperfect occupants of the folk-theoretical role of colour will be imperfect deservers of the name, but may nevertheless deserve it quite well enough.

But compromise has its limits. It won't do to say that colours do not exist; or that we are unable to detect them; or that they never are properties of material things; or that they go away when things are unilluminated or unobserved; or that they change with every change in the illumination, or with every change in an observer's visual capacities; or that the same surface of the same thing has different colours for different observers. Compromise on these points, and it becomes doubtful whether the so-called ‘colours’ posited in your theory are rightly so-called. Yet it is a Moorean fact that there are colours rightly so-called. Deny it, and the most credible explanation of your denial is that you are in the grip of some philosophical (or scientific) error.

FOLK PSYCHOPHYSICS

In other words, it is a Moorean fact that the folk psychophysics of colour is close to true.

Like other folk theories, the folk psychophysics of colour is a generally shared body of tacit belief. It concerns not only colours themselves, but also the inner states of colour experience that the colours tend to cause in us, and further inner states and behaviour that these colour experiences cause in turn.