A study of Wittgenstein on the logic of colour concepts. His remarks on the subject in the Tractatus are considered first, then the remarks he drafted when he returned to philosophy after a decade away fromit, then his treatment of colour concepts during the next two decades followed by the remarks in Remarks on Colour. The emphasis is on the problems he examines and the solutions he proposes. His discussion of colour incompatibility is defended, his examination of colour concepts in the 1930s and 1940s detailed and explained, and the remarks he composed at the end of his life considered with an eye to why they were written and what they add to remarks previously composed. It is argued that his aims are different from those normally attributed to him and, while he achieves a great deal, he does not resolve all the problems he tackles.