312 named colors tested for WCAG 2.2 accessibility

There is a hard ceiling, and it is arithmetic

Multiply a color's contrast with white by its contrast with black and you always get exactly 21. Across all 312 colors here the product ranges from 21 to 21 — it does not vary, because it cannot:

contrast(white) x contrast(black)
  = (1.05 / (L + 0.05)) x ((L + 0.05) / 0.05)
  = 1.05 / 0.05
  = 21

Three consequences follow, and none of them are facts about colour naming:

• Every colour passes AA with white or black. Failing both would need a product below 20.25. Ours is 21. 0 colors here fail both, and no dataset could produce a different answer.
• No colour can reach AAA with both. That would need a product of at least 49. 0 do, and none ever will.
• Passing AA with both is a razor-thin band — a product of at least 20.25 against a fixed 21. Exactly 3 colors here manage it.

What is a finding about named colors is the distribution: they cluster in the mid-to-light range, which is why white text fails on 69.9% of them while black text fails on only 29.2%.

The full index

Every color, both ratios, and the text color that actually works on it. Sortable by any column; filterable by family and by the best level the color reaches.

Take the data

Published under CC BY 4.0, the same licence as the rest of the Coloripedia dataset. Commercial use is fine; attribution is the only condition.

Methodology

Contrast is computed with the WCAG relative-luminance formula: each sRGB channel is divided by 255, linearised (c ≤ 0.04045 ? c/12.92 : ((c+0.055)/1.055)^2.4), weighted 0.2126 R + 0.7152 G + 0.0722 B, and the ratio taken as (Llighter + 0.05) / (Ldarker + 0.05).

Thresholds are taken directly from WCAG 2.2:

• SC 1.4.3 Contrast (Minimum) — AA: 4.5:1 normal text, 3:1 large text
• SC 1.4.6 Contrast (Enhanced) — AAA: 7:1 normal text, 4.5:1 large text

Large text means 18pt, or 14pt bold. Every color is treated as a background and tested against pure white and pure black text — the two choices a designer actually has by default. Ratios are rounded to two decimals for display; pass/fail is evaluated on the unrounded value, so a color showing 4.49 is a genuine fail rather than a rounding artefact.

Contrast ratio is not the whole of legibility — it says nothing about font weight, size beyond the two thresholds, or the surrounding surface. WCAG 2.2 keeps these thresholds from 2.0; the proposed APCA model in development for a future version scores some of these pairs differently.

Computed from the Coloripedia dataset on 2026-07-30. The figures on this page are generated from the data at build time, not transcribed — if the dataset changes, so do they.