Newton's colour wheel. Diagrams showing a colour wheel and how light is split by a prism into its constituent colours. These diagrams are by the English physicist, mathematician and astronomer Sir Isaac Newton (1643-1727). They were published in his famous work Opticks (1704). In this book, Newton published a number of his pioneering discoveries about the properties of light. Here, he is illustrating the separation of white light into its constituent colours with a prism. The colour wheel (centre right) has differing amounts of the colours, so that when it is spun, it appears white. The colour wheel is used to work out which colours cancel each other out. It also shows the order of the colours in the spectrum.