- Success Criterion 1.4.1
- Conformance level A
Calendar Availability Shown Only Through Colored Cells
1.4.1 — Use of Color
Scenario
Setting
A professional networking site's profile editor
What’s wrong
Calendar availability shown only via colored cells.
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 a calendar's available/unavailable days in grayscale: if color is the only distinguishing feature, 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 professional networking site's profile editor, this barrier is gone for people with color-vision deficiency — they no longer have to work around this.
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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