Palette Contrast Matrix

What it is for

A palette looks good as a row of swatches, but the real question comes later: which of these colors can carry text on which background? This tool takes up to 24 opaque colors and checks every ordered pair, with each color as text on every other color and on itself. You get the contrast ratio and the WCAG 2.2 decision for normal and large text.

Paste a plain HEX list, or the text of a GIMP GPL or JASC-PAL palette file. The tool only judges flat color pairs. It cannot see your font, the text's opacity or a photograph behind the words, so a passing pair is a good sign, not a certificate for a whole page.

Worked example

A four-color poster palette exported from a pixel editor as JASC-PAL with 224 122 95, 61 64 91, 129 178 154 and 244 241 222 (that is #E07A5F, #3D405B, #81B29A, #F4F1DE). The summary reads "4 colors with 16 foreground/background checks."

The interesting rows:

So the navy on cream works for everything, including body text at AAA. Navy on sage and coral on navy are fine for headlines only. Cream on coral fails even for large text, although it is a popular combination.

Thresholds really are exact: #777777 on white scores 4.48 and fails AA, while #767676 scores 4.54 and passes.

How to read the result

• Text is the foreground and Background the color behind it. Every pair appears in both directions; the ratio is the same either way, but you can scan by the role you need.
• Ratio runs from 1 (identical colors) to 21 (black on white). The table shows two decimals; the decisions use the unrounded value.
• AA needs 4.5:1 and AAA 7:1 for normal text. Large AA needs 3:1 and Large AAA 4.5:1. Large means at least 18 pt regular or 14 pt bold.
• Download contrast CSV contains every pair with the full-precision ratio and true/false columns for sorting in a spreadsheet.

Tips and common mistakes

• The diagonal (a color on itself) always shows 1 and fails. It is there so the matrix is complete; skip it.
• Use six-digit HEX values with #. Short forms like #fff, color names and transparent colors are rejected, and a list can hold 1–24 colors.
• A GPL file must start with GIMP Palette; a JASC file needs JASC-PAL, 0100 and a color count that matches its rows.
• Mid-tones are the trap. Colors around #777777 fall just short of 4.5:1 against both black and white.
• If nothing passes for body text, add a very dark and a very light neutral to the palette and run it again.

FAQ

Why does the table show the same ratio twice?

Contrast is symmetric. The matrix lists both directions so you can read it as "this text on that background" without swapping colors in your head.

Does a pass mean my page is accessible?

No. It means that color pair meets the contrast threshold for flat, opaque text. Font weight, size, transparency, images behind text and every other accessibility requirement still need checking.

Can I check a palette from Flipline or GIMP?

Yes. Paste the text of a .gpl or .pal file. Lumina's Palette Studio and Flipline export these formats.

Why is 4.48 a fail when it rounds to 4.5?

WCAG thresholds have no rounding. The tool compares the exact ratio with 4.5, so 4.48 fails.