Colour wheel
Hues arranged in a circle so that related colours sit side by side and opposites face each other.
Also: colour circle, hue circle
A colour wheel bends the band of the rainbow into a ring. Isaac Newton drew an early version in his book on optics, published in 1704, joining the red and violet ends. Later artists and teachers made many more. The wheel is a tool for choosing colours that work together: neighbours are harmonious, opposites give the strongest contrast. Different wheels exist. The painter's traditional wheel is built on red, yellow and blue. Wheels for screens and for printing use other starting colours, so their opposites differ slightly.