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#515151 on #4ade80 contrast ratio

4.55:1

Dark grey text (#515151) on a green (Tailwind green-400) background (#4ade80) meets WCAG 2.2 level AA for normal text. It passes 4 of 5 checks below.

Swap: #4ade80 on #515151

Large text sample

Normal body text in #515151 on #4ade80. The quick brown fox jumps over the lazy dog.

WCAG 2.2 results

WCAG 2.2 contrast results for #515151 on #4ade80
Normal text — WCAG 1.4.3 AA4.5:1Pass
Large text — WCAG 1.4.3 AA3:1Pass
UI components & icons — WCAG 1.4.11 AA3:1Pass
Normal text — WCAG 1.4.6 AAA7:1Fail
Large text — WCAG 1.4.6 AAA4.5:1Pass

Nearest passing colours

How it looks with colour blindness

Simulated with the Machado et al. (2009) model at full severity.

  • Aa

    Protanopia (no red cones)

    4.93:1

  • Aa

    Deuteranopia (no green cones)

    4.29:1

  • Aa

    Tritanopia (no blue cones)

    4.51:1

  • Aa

    Achromatopsia (no colour)

    4.55:1

Try a different pair

Colours

Hex, rgb() or hsl(). Alpha is composited.

Permalink

Preview

Large heading text

Normal body text at 14 px. The quick brown fox jumps over the lazy dog.

Outlined buttonA text link

Colour-blindness preview

Simulated with Machado et al. (2009), full severity.

  • AaProtanopia (no red cones)4.93:1
  • AaDeuteranopia (no green cones)4.29:1
  • AaTritanopia (no blue cones)4.51:1
  • AaAchromatopsia (no colour)4.55:1

Contrast ratio

4.55:1

WCAG 2.2 contrast verdicts
CheckCriterionNeedsResult
Normal text1.4.3 AA4.5:1Pass
Large text1.4.3 AA3:1Pass
UI components & graphics1.4.11 AA3:1Pass
Normal text1.4.6 AAA7:1Fail
Large text1.4.6 AAA4.5:1Pass

Nearest passing colours

Same hue, lightness adjusted in OKLCH.

AA — 4.5:1

Already passes.

AAA — 7:1

Change text

#353535 · 7.03:1

Change background: no colour with this hue reaches the target.

Large text means at least 24 CSS px, or 18.66 CSS px bold. Ratios are truncated, never rounded, so 4.49:1 is shown as failing 4.5:1.

Questions about this pair

Is #515151 on #4ade80 accessible?
Yes for WCAG 2.2 level AA: the contrast ratio is 4.55:1, above the 4.5:1 needed for normal text. It does not reach the 7:1 needed for AAA.
What is the contrast ratio of #515151 and #4ade80?
4.55:1, calculated with the WCAG 2.2 relative luminance formula. The ratio is truncated, not rounded, so it never shows a failing pair as passing.
What colour passes AA on #4ade80?
#353535 is the closest colour to #515151 — same hue, adjusted lightness — that reaches 4.5:1 on #4ade80.

Related colour pairs