This book offers a comprehensive introduction in to the various theories of colour and how they developed over the centuries and millennia. As colour is the perception of light by our brains, the book captures not only the physical phenomena but also psychological and philosophical aspects of colours. It starts with ancient studies of Greek philosophers and their insights into light and mirrors, then reviews the theory of colors in the middle ages in Europe and Middle East. The last big part of the book explains the theories of colours by modern scientists and philosophers, starting with Isaac Newton and ending colour schemes of modern digital pictures.