Idea

Complementary colors

Every color has an opposite, but which one depends on the map: the painter's wheel, light, or your eye.

Painter's wheel (RYB): Red–green, blue–orange, yellow–violet
Light and afterimages: Red–cyan, green–magenta, blue–yellow
Opponent axes (Hering, CIELAB): Red–green, yellow–blue

Complementary colors are pairs that sit opposite each other, but opposite on which map? There are three common answers, and they disagree. On the painter's red-yellow-blue wheel, the pairs are red–green, blue–orange and yellow–violet. In light, and in the afterimages your eye makes, they are red–cyan, green–magenta and blue–yellow. On perceptual maps like CIELAB, built so equal distances look equally different, the hue opposite a red is a blue-green close to teal.

You can test the eye's version yourself. Stare at a red dot for thirty seconds, then look at a white page, and a blue-green ghost floats there: cyan-ish, not the plain green of the painter's wheel. The cells that were busy reporting red tire, so the balance tips the other way. Deeper in the visual system, color is coded as opponent pairs, red against green and blue against yellow, as Ewald Hering proposed in 1878, which is why no one sees a 'reddish green' (see how eyes see color).

Side by side, opposites make each other look stronger, and painters have leaned on that for two centuries. Chevreul made it part of his law of simultaneous contrast in 1839. The Impressionists set orange light against blue-violet shadows, and Van Gogh, thinking in painter's-wheel pairs, said that in his Night Café he tried to show “the terrible passions of humanity by means of red and green.”

Mixed, opposites cancel. Two opposite lights add up to white or grey. Two opposite paints dull each other toward a neutral grey, brown or near-black, depending on the paints. Seurat set complementary dots side by side across A Sunday on La Grande Jatte instead of mixing them. Designers use complements for pop, like a tangerine button on a navy page; one complement as an accent usually beats a fifty-fifty split.

Swatches

Painter's wheel · red #D62F2F
Painter's wheel · its opposite, green #2E9A4F
Painter's wheel · blue #2563C9
Painter's wheel · its opposite, orange #F07A1A
Light and afterimage · red #D62F2F
Light and afterimage · its opposite, cyan #00FFFF
Light and afterimage · green #2E9A4F
Light and afterimage · its opposite, magenta #FF00FF
CIELAB · red #D62F2F
CIELAB · its opposite, blue-green #1D919F

Colors

Sources

Chevreul, M. E. (1839). De la loi du contraste simultané des couleurs. Paris.
Van Gogh, V. Letter to Theo, 8 September 1888. Van Gogh Museum, vangoghletters.org.
Hering, E. (1878). Zur Lehre vom Lichtsinne. Vienna.
Fairchild, M. D. (2013). Color Appearance Models, 3rd ed. Wiley.

Open in Chromatlas

Hex values are screen approximations. Every page lists its sources.