---
name: Complementary colors
slug: complementary-colors
category: color
status: published
created: 2026-08-21T00:00:00.000Z
modified: 2026-08-21T00:00:00.000Z
definition: Two hues sitting opposite each other on the colour wheel, the
  pairing that produces the strongest contrast and the loudest accent.
aliases:
  - name: opposite colors
    source: community
  - name: contrasting colors
    source: community
  - name: split-complementary
tags:
  - perception
relations:
  contrastWith:
    - triadic-colors
    - analogous-colors
  variantOf: []
  partOf: []
  seeAlso:
    - hue
implementations: []
sources:
  - title: "Design Glossary: Basic Color Terminology"
    url: https://design4users.com/basic-color-terminology/
demo: inline
exhibit: false
useWhen: the loudest possible pairing of two hues
---

Two colours are complementary when their hues are half a turn apart. Because they are as
far from each other as the wheel allows, no other pairing separates them further, which is
what makes the combination read as deliberate rather than accidental: one colour has
nowhere further to go from the other.

Which pairs those are depends entirely on whose wheel is being used, and this is the part
that causes arguments. On the red, yellow, blue wheel taught in art classes, red pairs with
green, blue with orange, and yellow with purple. On the additive wheel that screens
actually work in, red pairs with cyan, green with magenta, and blue with yellow. A
perceptual wheel such as the one `oklch` describes gives a third set of numbers again. All
three are correct within their own model, so "the complement of red" is only a well posed
question once you say which wheel you mean.

Complementary pairs are loud on purpose, and they misbehave when used in equal measure. Set
two fully saturated complements at the same lightness side by side and the shared edge
appears to shimmer, an effect of the eye rather than the screen, and each colour makes the
other look more intense than it is. The conventional fix is to refuse the symmetry: give
one hue most of the area and the other a small fraction of it, and separate them in
[lightness](/lightness) as well as in [hue](/hue). Softer relatives exist for when the full
pair is too much, notably the split complementary (one colour plus the two hues either side
of its opposite) and the triad.

In interfaces the pairing is usually a job rather than a scheme: the brand hue carries the
surface and the navigation, and its complement is spent on exactly one thing, the sale
badge or the primary action, precisely because nothing else on the screen can compete with
it. Two cautions. Hue opposition provides no lightness difference at all, so a complement
never satisfies a text contrast requirement on its own. And red with green, the most famous
pair of all, is the one that the most common colour vision deficiencies flatten into a
single muddy hue.