The colour wheel is a representation of all the visible colours. There are actually several colour wheels, and one can be made for every colour space. One of the first colour wheels was created in 1708 by Claude Boudet, a contemporary to Issac Newton.
Traditionally, the colour wheel most commonly used is a subtractive one, using RGB – Red, Yellow, and Blue as the primary colours. Other wheels are also common, such as CMYK and RGB.