#4f46e5 on #000000 contrast ratio
3.33:1
Blue (Tailwind indigo-600) text (#4f46e5) on a black background (#000000) is only acceptable for large text and UI components under WCAG 2.2. It passes 2 of 5 checks below.
Swap: #000000 on #4f46e5Large text sample
Normal body text in #4f46e5 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 | Pass |
| UI components & icons — WCAG 1.4.11 AA | 3:1 | Pass |
| 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)
4.12:1
- Aa
Deuteranopia (no green cones)
3.52:1
- Aa
Tritanopia (no blue cones)
3.76:1
- Aa
Achromatopsia (no colour)
3.33:1
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)4.12:1
- AaDeuteranopia (no green cones)3.52:1
- AaTritanopia (no blue cones)3.76:1
- AaAchromatopsia (no colour)3.33:1
Contrast ratio
3.33:1
| Check | Criterion | Needs | Result |
|---|---|---|---|
| Normal text | 1.4.3 AA | 4.5:1 | Fail |
| Large text | 1.4.3 AA | 3:1 | Pass |
| UI components & graphics | 1.4.11 AA | 3:1 | Pass |
| 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
#5f5efd · 4.50:1
Change background
#dbdbdb · 4.54:1
AAA — 7:1
Change text
#838aff · 7.04:1
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 #4f46e5 on #000000 accessible?
- Only for large text. At 3.33:1 it meets the 3:1 large-text and UI-component thresholds but fails the 4.5:1 needed for normal body text.
- What is the contrast ratio of #4f46e5 and #000000?
- 3.33:1, 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?
- #5f5efd is the closest colour to #4f46e5 — same hue, adjusted lightness — that reaches 4.5:1 on #000000.
Related colour pairs
- Aa 1.11:1#eef2ff on #ffffff · Fails
- Aa 1.11:1#ffffff on #eef2ff · Fails
- Aa 18.78:1#eef2ff on #000000 · AAA
- Aa 18.78:1#000000 on #eef2ff · AAA
- Aa 1.23:1#e0e7ff on #ffffff · Fails
- Aa 1.23:1#ffffff on #e0e7ff · Fails
- Aa 17.04:1#e0e7ff on #000000 · AAA
- Aa 17.04:1#000000 on #e0e7ff · AAA
- Aa 1.49:1#c7d2fe on #ffffff · Fails
- Aa 1.49:1#ffffff on #c7d2fe · Fails
- Aa 14.07:1#c7d2fe on #000000 · AAA
- Aa 14.07:1#000000 on #c7d2fe · AAA