---
name: Use of color
slug: use-of-color
category: accessibility
status: published
created: 2026-08-21T00:00:00.000Z
modified: 2026-08-28T00:00:00.000Z
definition: The rule that colour must never be the only carrier of meaning, so a
  red field also needs an icon, wording, or shape change.
aliases:
  - name: colour alone
    source: wcag
  - name: don't rely on color
    source: community
  - name: redundant coding
    source: community
  - name: pattern fill
    source: community
  - name: texture encoding
    source: community
  - name: color alone
    source: merged-candidate
  - name: color as the only cue
    source: merged-candidate
  - name: color-only information
    source: merged-candidate
  - name: greyscale test
    source: merged-candidate
  - name: grayscale test
    source: merged-candidate
tags:
  - dataviz
  - perception
  - wcag
relations:
  contrastWith:
    - color-vision-deficiency
    - sensory-characteristics
    - color-coding
  variantOf: []
  partOf: []
  seeAlso:
    - contribution-graph
implementations:
  - system: carbon
    name: Use of color and color blindness
    url: https://carbondesignsystem.com/guidelines/accessibility/color/
sources:
  - title: "WCAG 2.2: Use of Color"
    url: https://www.w3.org/TR/WCAG22/#use-of-color
demo: inline
exhibit: false
useWhen: the only difference between two states is hue
---

WCAG's success criterion 1.4.1 is one sentence long and it bans one thing: colour as the
only visual means of conveying information, indicating an action, prompting a response,
or distinguishing one element from another. Colour is not the problem. Colour carrying
the message by itself is. Red-green colour vision deficiency runs at roughly 8 percent of
men and half a percent of women, which in most products is a larger group than every
screen reader user combined, and it is joined by anyone reading on a washed-out phone in
sunlight, on a cheap projector, through a monochrome print, or with a tinted display
filter on for the evening.

The fix is redundancy, and it is usually cheap. A required field gets an asterisk or the
word "required" beside its red label. An [error message](/error-message) gets a warning
glyph and a sentence, not just a red border. A [link](/link) inside a paragraph gets an
[underline](/underline) as well as a hue, because "blue means clickable" is a convention
the reader has to be able to see. Chart series get a pattern fill or a direct label
instead of a legend that maps hue to name. Status rows get a word next to the dot, which
is what makes [status colour](/status-color) safe to use at all. The test is quick: view
the screen in greyscale and ask whether every distinction the design was making survives.

It is worth keeping this criterion apart from the contrast ones, because they get merged
in review and they ask different questions. 1.4.1 is about redundancy: is there a second
cue at all? [Contrast ratio](/contrast-ratio) (1.4.3) and non-text contrast (1.4.11) are
about legibility: can these two colours be told apart from each other in the first place?
A red error message can pass contrast perfectly and still fail 1.4.1, and a design with
icons on every state can satisfy 1.4.1 while its grey-on-grey label fails contrast. Both
have to hold.

The one exemption people reach for wrongly is the parenthetical about colour that a
person is told about in text. That covers a wine list saying which entries are marked in
green, not a dashboard hoping the reader will work it out. If the only way to explain a
state is to write a sentence about the palette, the state needed a shape.