#A31B21
Closest named color: Auburn (#9B2226). oklch(46.3% 0.17 25.3), rgb(163, 27, 33).
Aa
White text reads best on this color (7.67:1).
About this color
#A31B21 is a medium-dark, vivid red. In OKLCH its lightness is 46%, its chroma 0.170 and its hue 25°. Its hue sits on the warm side of the wheel. The nearest named color is Auburn (#9B2226), ΔE 0.016 away. White text reads best on it, at 7.67:1.
| Hue family | Reds |
| Lightness | medium-dark (46%) |
| Chroma | vivid (0.170) |
| Temperature | warm |
| Nearest name | Auburn (#9B2226) |
| Black text | 2.73:1 |
| White text | 7.67:1 |
Values
| HEX | #A31B21 |
| RGB | rgb(163, 27, 33) |
| HSL | hsl(357, 72%, 37%) |
| OKLCH | oklch(46.3% 0.17 25.3) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #A31B21 | 7.67:1 | AAA | Lc -89.9 | Fine for body text |
| Black text on #A31B21 | 2.73:1 | Fails | Lc 19.1 | Dividers and decoration only |
| #A31B21 text on white | 7.67:1 | AAA | Lc 85.0 | Fine for body text |
| #A31B21 text on black | 2.73:1 | Fails | Lc -17.0 | Dividers and decoration only |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 700.
-
Step 50
50
#FDF3F2
oklch(97.2% 0.011 24.3)
-
Step 100
100
#FAE4E2
oklch(93.6% 0.024 23.9)
-
Step 200
200
#F6CECA
oklch(88.4% 0.046 24.8)
-
Step 300
300
#F1ACA6
oklch(80.8% 0.082 24.6)
-
Step 400
400
#E77D76
oklch(70.6% 0.132 24.9)
-
Step 500
500
#DD5752
oklch(63.1% 0.169 25.3)
-
Step 600
600
#C83637
oklch(55.6% 0.183 25.1)
-
Step 700
700 (this color)
#A31B21
oklch(46.3% 0.17 25.3)
-
Step 800
800
#8C2323
oklch(42.7% 0.141 25.5)
-
Step 900
900
#712321
oklch(37.7% 0.111 25.4)
-
Step 950
950
#421614
oklch(26.9% 0.069 25.4)
#A31B21 with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #48411F | 0.186 |
| Deuteranopia (no green cones) | #695D1B | 0.168 |
| Tritanopia (no blue cones) | #B4001F | 0.034 |
| Achromatopsia (no color) | #535353 | 0.172 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #A31B21
#A31B21
oklch(46.3% 0.17 25.3)
- #00656E
#00656E
oklch(46.3% 0.079 205.5)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #A31B21, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Auburn #9B2226 ΔE 0.016
- Brown #A52A2A ΔE 0.020
- Burnt Red #9F2305 ΔE 0.025
- Carmine #9D0216 ΔE 0.025
- Rufous #AE2012 ΔE 0.029
- Rust Red #AA2704 ΔE 0.033
- Deep Red #9A0200 ΔE 0.035
- Rouge #AB1239 ΔE 0.035
Use #A31B21 in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.