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Accessible Color Contrast Palette

Compare text and background colors, review WCAG contrast ratios, and assemble a more accessible interface palette.

ToolRuns in the browser
Accessible Color Contrast Palette working example

Compare text and background colors, review WCAG contrast ratios, and assemble a more accessible interface palette.

Runs in your browser
Sample result
Example Accessible Color Contrast Palette result
Proportion result
- Missing value x: 12
- Cross-products: 2×12 = 3×8 = 24
- Review the input unit and rounding rule
Next step: compare the two cross-products or test a second known proportion
The interactive tool loads in this area when JavaScript is enabled.

How to use Accessible Color Contrast Palette

Common uses include Check color contrast, Choose readable UI pairs, Document accessible palette options.

  • Open Accessible Color Contrast Palette and enter the three known values in a:b = c:x.
  • Keep a, b, and c in compatible units and make sure the divisor is not zero. Focus first on Check color contrast.
  • Calculate x, then compare a×x with b×c to verify the proportion. Use the next pass to Document accessible palette options.
  • Record x together with the input values, unit, and rounding rule before you Choose readable UI pairs.

Useful for

  • Check color contrast
  • Choose readable UI pairs
  • Document accessible palette options

Common issues

The result is undefined or infinite.

Make sure the value used as the divisor is not zero and that every known field contains a number.

The proportion is numerically correct but the real quantity is wrong.

Convert all inputs to compatible units before calculating and keep the unit with the result.

How to interpret the result

Use x only after confirming the proportion order, compatible units, cross-products, and rounding precision.

Related workflow

Next path: Accessible Color Contrast Palette -> Accessible Name Calculator -> APCA Contrast Calculator. Keep the original input nearby so you can compare each result before using it elsewhere.

Privacy and review notes

This tool is designed to process inputs in the browser where the workflow allows it. Photo and AI-assisted outputs are previews or references and should be checked before publishing. Use non-sensitive examples and review the output before sharing or submitting it.