In this text, Michael Watkins endorses the Moorean view that colours are simple, non-reducible, properties of objects. He breaks from what has become the received view that either colours are reducible to certain properties of interest to science, or else nothing is really coloured. What is novel about the work is that Watkins, unlike other Mooreans, takes seriously the metaphysics of colours. Consequently, Watkins provides an account of what colours are, how they are related to the physical properties on which they supervene, and how colours can be causally efficacious without the threat of causal overdetermination. Along the way, he provides accounts of normal conditions and non-human colour properties. The book should be of interest to any metaphysician and philosopher of mind interested in colours and colour perception.