Contrast

Patch UI assigns a WCAG target to every readable token role and filled-label pair. The repository checks those exact relationships in both themes and fails CI when a token change breaks the contract.

Contract

• Primary ink text clears AAA on the application canvas, layers, and neutral fills.
• Secondary ink-muted text clears AA on its supported surfaces.
• Placeholder and disabled tiers clear the large-text or nonessential 3:1 target on base.
• Primary Button labels clear AAA, while semantic status labels clear AA on their paired fills.

Run the same check locally after changing readable color tokens:

Current matrix

The matrix reads active CSS variables from the page, so switching between light and dark mode updates the displayed values and ratios immediately.

Choosing a text tier

• Use ink for headings, body copy, and information people must read precisely.
• Use ink-muted for secondary labels, metadata, and the default icon tone.
• Use ink-subtle for placeholders or missing-value copy on the base canvas.
• Use ink-tertiary for disabled hints and nonessential footnotes, not required instructions.

On lifted or filled surfaces, prefer ink-muted unless the intended token pair is explicitly covered by the contract.

After customizing tokens

1. Change primary, ink, base, layer, or fill values in patch-ui-tokens.css.
2. Run the contrast command.
3. Review the affected components in both light and dark mode.
4. Test any additional consumer-defined combinations not represented by the shipped contract.

The checker parses the repository token file. It does not evaluate arbitrary opacity, gradients, imagery, browser extensions, or downstream CSS overrides.