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Use of Color (1.4.1)

Color must not be the only means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.

WCAG Reference

Applies to: WCAG 2.0, WCAG 2.1, WCAG 2.2 Introduced in: WCAG 2.0 | Level: A | Read the official specification →

What this rule checks​

The scanner flags instances where meaning is communicated exclusively through color without a secondary visual indicator such as text, icons, patterns, or underlines.

Why it matters​

Users with color-vision deficiency, low vision, or monochrome displays cannot distinguish elements when the only differentiator is color. Adding a secondary cue ensures everyone perceives the intended meaning.

Common failure patterns​

  • required form fields marked only with red text
  • chart series differentiated only by color with no patterns or labels
  • links within body text that are distinguished only by color (no underline or icon)
  • status indicators (success/error) using only green/red with no text or icon

Remediation guidance​

  • pair color with a text label, icon, pattern, or border change
  • underline links or add a visible icon to distinguish them from surrounding text
  • use patterns, hatching, or data labels in charts alongside color
  • test the interface with a color-blindness simulator to confirm the secondary cue is visible
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