#0c4a6e on #000000 contrast ratio
2.22:1
Very dark blue (Tailwind sky-900) text (#0c4a6e) on a black background (#000000) fails every WCAG 2.2 contrast threshold.
Swap: #000000 on #0c4a6eLarge text sample
Normal body text in #0c4a6e 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)
2.41:1
- Aa
Deuteranopia (no green cones)
2.10:1
- Aa
Tritanopia (no blue cones)
2.37:1
- Aa
Achromatopsia (no colour)
2.22:1
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)2.41:1
- AaDeuteranopia (no green cones)2.10:1
- AaTritanopia (no blue cones)2.37:1
- AaAchromatopsia (no colour)2.22:1
Contrast ratio
2.22:1
| 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
#427aa0 · 4.52:1
Change background
#b3b3b3 · 4.51:1
AAA — 7:1
Change text
#639bc3 · 7.00:1
Change background
#dedede · 7.03:1
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 #0c4a6e on #000000 accessible?
- No. At 2.22:1 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 #0c4a6e and #000000?
- 2.22:1, 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?
- #427aa0 is the closest colour to #0c4a6e — same hue, adjusted lightness — that reaches 4.5:1 on #000000.
Related colour pairs
- Aa 1.06:1#f0f9ff on #ffffff · Fails
- Aa 1.06:1#ffffff on #f0f9ff · Fails
- Aa 19.69:1#f0f9ff on #000000 · AAA
- Aa 19.69:1#000000 on #f0f9ff · AAA
- Aa 1.14:1#e0f2fe on #ffffff · Fails
- Aa 1.14:1#ffffff on #e0f2fe · Fails
- Aa 18.30:1#e0f2fe on #000000 · AAA
- Aa 18.30:1#000000 on #e0f2fe · AAA
- Aa 1.32:1#bae6fd on #ffffff · Fails
- Aa 1.32:1#ffffff on #bae6fd · Fails
- Aa 15.82:1#bae6fd on #000000 · AAA
- Aa 15.82:1#000000 on #bae6fd · AAA