What are colours? How do they fit into the physical world, and what is the relation between colours and colour experiences? Should we explain colours in terms of colour experiences, such that, e.g., for something to be red just is for it to look red to normal observers under standard conditions? Or are colour experiences, when they are veridical, best understood as responses to objective colour properties that are independent of such experiences? This course will explore different theories of the nature of colours and how they relate to colour experiences. Topics to be covered may include dispositionalist theories of colours, eliminativist theories, physicalist theories, and primitivist theories.