#581c87 on #000000 contrast ratio
1.93:1
Dark purple (Tailwind purple-900) text (#581c87) on a black background (#000000) fails every WCAG 2.2 contrast threshold.
Swap: #000000 on #581c87Large text sample
Normal body text in #581c87 on #000000. The quick brown fox jumps over the lazy dog.
WCAG 2.2 results
| Normal text — WCAG 1.4.3 AA | 4.5:1 | Fail |
|---|---|---|
| Large text — WCAG 1.4.3 AA | 3:1 | Fail |
| UI components & icons — WCAG 1.4.11 AA | 3:1 | Fail |
| Normal text — WCAG 1.4.6 AAA | 7:1 | Fail |
| Large text — WCAG 1.4.6 AAA | 4.5:1 | Fail |
Nearest passing colours
AA (4.5:1)
AAA (7:1)
How it looks with colour blindness
Simulated with the Machado et al. (2009) model at full severity.
- Aa
Protanopia (no red cones)
1.99:1
- Aa
Deuteranopia (no green cones)
2.00:1
- Aa
Tritanopia (no blue cones)
2.01:1
- Aa
Achromatopsia (no colour)
1.93:1
Try a different pair
Colours
Hex, rgb() or hsl(). Alpha is composited.
Preview
Large heading text
Normal body text at 14 px. The quick brown fox jumps over the lazy dog.
Colour-blindness preview
Simulated with Machado et al. (2009), full severity.
- AaProtanopia (no red cones)1.99:1
- AaDeuteranopia (no green cones)2.00:1
- AaTritanopia (no blue cones)2.01:1
- AaAchromatopsia (no colour)1.93:1
Contrast ratio
1.93:1
| Check | Criterion | Needs | Result |
|---|---|---|---|
| Normal text | 1.4.3 AA | 4.5:1 | Fail |
| Large text | 1.4.3 AA | 3:1 | Fail |
| UI components & graphics | 1.4.11 AA | 3:1 | Fail |
| Normal text | 1.4.6 AAA | 7:1 | Fail |
| Large text | 1.4.6 AAA | 4.5:1 | Fail |
Nearest passing colours
Same hue, lightness adjusted in OKLCH.
AA — 4.5:1
Change text
#915bc7 · 4.52:1
Change background
#a7a7a7 · 4.52:1
AAA — 7:1
Change text
#b37cec · 7.01:1
Change background
#d0d0d0 · 7.05:1
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 #581c87 on #000000 accessible?
- No. At 1.93:1 it fails every WCAG 2.2 text contrast threshold, including the 3:1 minimum for large text and UI components.
- What is the contrast ratio of #581c87 and #000000?
- 1.93:1, 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 #000000?
- #915bc7 is the closest colour to #581c87 — same hue, adjusted lightness — that reaches 4.5:1 on #000000.
Related colour pairs
- Aa 1.07:1#faf5ff on #ffffff · Fails
- Aa 1.07:1#ffffff on #faf5ff · Fails
- Aa 19.56:1#faf5ff on #000000 · AAA
- Aa 19.56:1#000000 on #faf5ff · AAA
- Aa 1.17:1#f3e8ff on #ffffff · Fails
- Aa 1.17:1#ffffff on #f3e8ff · Fails
- Aa 17.79:1#f3e8ff on #000000 · AAA
- Aa 17.79:1#000000 on #f3e8ff · AAA
- Aa 1.36:1#e9d5ff on #ffffff · Fails
- Aa 1.36:1#ffffff on #e9d5ff · Fails
- Aa 15.42:1#e9d5ff on #000000 · AAA
- Aa 15.42:1#000000 on #e9d5ff · AAA