Why grey #999 fails
Light grey text on white looks elegant in a mock-up. On a phone in daylight, or for someone with low vision, it is simply missing.
The rule
WCAG criterion 1.4.3 asks for a contrast of at least 4.5 to 1 between normal text and its background. Large text, from 24 px or from about 19 px in bold, needs at least 3 to 1.
The numbers
- Grey #999 on white: 2.85 to 1. Fails for normal text and for large text.
- Grey #767676 on white: 4.54 to 1. The lightest grey that passes for normal text.
- Black on white: 21 to 1, the maximum.
The ratio compares how much light the two colours give off. A pale blue link can fail in the same way a pale grey caption does.
Where it hides
Look beyond body text: placeholder text in forms, captions under pictures, footer links, buttons that look disabled but are active, and white text laid over photographs.
How we report it
Each gap gets its own card in the report: the criterion number, the address and place on the page, the measured ratio and a replacement colour. After your fixes we check it again at the re-test.