- Success Criterion 1.4.1
- Conformance level A
Highlighted Text Meant to Signal Importance by Color Alone
1.4.1 — Use of Color
Scenario
Setting
A coworking-space booking app
What’s wrong
Text highlighted in color to mean "important/changed" with no other cue (interacts with 1.3.1).
Example
<span class="required-field"></span> <!-- red asterisk only -->Why it matters
People with color-vision deficiency, low vision, or constrained viewing conditions such as strong glare.
How to test
View text highlighted to mean 'important' or 'changed' in grayscale: if the highlight's meaning disappears, it fails.
How to fix
A second visual cue (text, underline, icon, or pattern) must convey the information alongside color.
<span class="required-field">* <span class="visually-hidden">required</span></span>Color alone (a red dot or border) can't be the only signal — pair it with text or an icon plus label.
Outcome
On a coworking-space booking app, this barrier is gone for people with color-vision deficiency — they reach the same outcome without extra effort.
Who is affected
People with color-vision deficiency, low vision, or constrained viewing conditions such as strong glare.
Learn more
- Understanding Understanding document (opens in a new tab)
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