The color wheel
Bend the rainbow into a circle and you get the most useful diagram in color.
- Early color circle
- Newton, Opticks, 1704
- Red-yellow-blue wheel
- Moses Harris, c. 1766
A color wheel bends the rainbow into a loop, so red at one end meets violet at the other, joined by purples the rainbow doesn't contain. Isaac Newton drew one of the first color circles in his Opticks (1704), sizing its seven slices to match the intervals of a musical scale.
Painters wanted a wheel for mixing paint, not light. Around 1766 the English engraver Moses Harris printed a wheel built on three 'principal' colors, red, yellow and blue, with orange, green and purple mixed between. That red-yellow-blue wheel is still the one in art classrooms. Goethe drew his own in his Theory of Colours, and Johannes Itten, who taught at the Bauhaus, popularized the 12-part wheel many painters learn today.
The red-yellow-blue wheel is a tradition more than a measurement. It spaces red, yellow and blue evenly, though to the eye red and yellow are much closer, and no mix of those three paints gives a clean magenta or cyan. Screens mix light from red, green and blue, so on a screen's wheel the opposite of red is a cyan like aqua, not green. Printers build theirs on cyan, magenta and yellow ink. Each wheel suits its own job: light, ink or paint.
A wheel earns its place in three ways: it helps predict what a mix will give, it maps how hues relate, and it turns harmony ideas into geometry, with neighbors, opposites and triangles. Just remember that which colors count as opposites changes from wheel to wheel, and that a flat wheel leaves out lightness, the dimension that matters most (see value).
Swatches
- Red · RYB 'primary' (tradition)
- Orange · RYB secondary
- Yellow · RYB 'primary' (tradition)
- Green · RYB secondary
- Blue · RYB 'primary' (tradition)
- Purple · RYB secondary
Colors
Sources
- Newton, I. (1704). Opticks. Book I, Part II.
- Harris, M. (c. 1766). The Natural System of Colours. Royal Academy of Arts collection.
- Gage, J. (1993). Colour and Culture. Thames & Hudson.
Hex values are screen approximations. Every page lists its sources.