Palette Accessibility Audit

A palette accessibility audit is an automated check that tests every possible foreground and background combination in a color palette against the contrast ratios defined by WCAG 2.1.

Instead of checking colors one pair at a time, the audit builds a full matrix and flags exactly which combinations pass AA, pass AAA, or fail. You get a single report showing where your palette is safe to use for text, UI components, and icons.

You can audit up to 10 colors in a single run. That produces a 10 by 10 contrast matrix with 100 foreground and background combinations, which is enough to cover most product design systems including brand colors, neutrals, and semantic states like success, warning, and error.

For very large enterprise systems, audit one logical group at a time, such as neutrals, then brand colors, then status colors.

The audit checks the four thresholds defined in WCAG 2.1: 4.5 to 1 for normal text at Level AA, 3 to 1 for large text at Level AA, 7 to 1 for normal text at Level AAA, and 4.5 to 1 for large text at Level AAA.

It also flags the 3 to 1 minimum required by Success Criterion 1.4.11 Non-text Contrast, which applies to user interface components, form input borders, focus indicators, and meaningful graphical objects.

Large text is defined as 18 point and above, or 14 point and above when rendered in bold. At typical browser defaults that works out to roughly 24 CSS pixels for regular weight and 19 CSS pixels for bold.

Large text gets a more relaxed 3 to 1 minimum at Level AA because larger letterforms remain readable at lower contrast than body copy.

When a pair fails, you usually do not want to abandon the color entirely because it carries brand meaning. The audit calculates the smallest perceptual shift, usually a lightness adjustment in HSL or OKLCH, that pushes the pair into the passing zone while preserving hue and saturation as closely as possible.

That lets you stay on-brand while fixing accessibility violations, instead of throwing the palette out and starting over.

Yes. Contrast is necessary but not sufficient. A palette that passes WCAG contrast can still fail for users with color vision deficiency if you rely on color alone to convey information, such as marking errors only in red.

After the audit, you should also simulate the palette under common forms of color blindness, check focus indicator visibility, and confirm you are not using color as the only channel for state, status, or required form fields.