Color
Contrast is not a checkbox
Meeting the contrast ratio is necessary and not sufficient. The failures that hurt most are the ones where color is the only thing carrying the meaning, and a ratio never sees those.
Devin Okafor, Co-founder and CTO · June 3, 2026 · 5 minute read
Color contrast is the one accessibility rule everybody has heard of, and it is genuinely important. Text below the WCAG AA ratio is hard or impossible to read for people with low vision, and that is a large group. If your body text is light gray on white, fix it today.
- 4.5:1
- minimum contrast for normal text, AA
- 3:1
- minimum for large text and UI components
- 7:1
- the stricter AAA target for body text
The failure a ratio cannot see
Here is the harder problem. Contrast tools check whether text is legible against its background. They cannot check whether color is the only way you are telling the reader something. And that failure, meaning carried by color alone, blocks people that a ratio check would wave through.
Two states, told apart by color alone
<span class="dot green"></span> Passing
<span class="dot red"></span> FailingThe fix is to add a second signal: an icon, a label, a shape, a pattern. Do not take the color away, add something alongside it, so the meaning survives when the color does not.
Meaning that survives without color
<span class="dot green">✓</span> Passing
<span class="dot red">✕</span> FailingA green dot and a red dot are the same dot to a lot of your users. Give them a second way to tell.
Devin Okafor
This is the pattern across accessibility: the mechanical part is the easy part, and the judgement is where people are actually helped or left out. Tallyn runs the ratio checks, and it also reasons about whether color is doing work that nothing else backs up, which is the finding that a checkbox will never give you.