#A31B1B
Closest named color: Auburn (#9B2226). oklch(46.3% 0.171 27.2), rgb(163, 27, 27).
Aa
White text reads best on this color (7.69:1).
About this color
#A31B1B is a medium-dark, vivid red. In OKLCH its lightness is 46%, its chroma 0.171 and its hue 27°. Its hue sits on the warm side of the wheel. The nearest named color is Auburn (#9B2226), ΔE 0.018 away. White text reads best on it, at 7.69:1.
| Hue family | Reds |
| Lightness | medium-dark (46%) |
| Chroma | vivid (0.171) |
| Temperature | warm |
| Nearest name | Auburn (#9B2226) |
| Black text | 2.72:1 |
| White text | 7.69:1 |
Values
| HEX | #A31B1B |
| RGB | rgb(163, 27, 27) |
| HSL | hsl(0, 72%, 37%) |
| OKLCH | oklch(46.3% 0.171 27.2) |
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 #A31B1B | 7.69:1 | AAA | Lc -89.9 | Fine for body text |
| Black text on #A31B1B | 2.72:1 | Fails | Lc 19.0 | Dividers and decoration only |
| #A31B1B text on white | 7.69:1 | AAA | Lc 85.0 | Fine for body text |
| #A31B1B text on black | 2.72:1 | 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
#FDF3F1
oklch(97.1% 0.011 31.1)
-
Step 100
100
#FAE4E1
oklch(93.6% 0.025 26.9)
-
Step 200
200
#F6CEC9
oklch(88.4% 0.046 26.4)
-
Step 300
300
#F2ADA4
oklch(81% 0.083 27.3)
-
Step 400
400
#E77E73
oklch(70.7% 0.131 27.1)
-
Step 500
500
#DD584E
oklch(63.2% 0.169 27.2)
-
Step 600
600
#C83631
oklch(55.5% 0.184 27.1)
-
Step 700
700 (this color)
#A31B1B
oklch(46.3% 0.171 27.2)
-
Step 800
800
#8C231F
oklch(42.7% 0.141 27.2)
-
Step 900
900
#71231F
oklch(37.7% 0.111 26.7)
-
Step 950
950
#421613
oklch(26.9% 0.069 26.6)
#A31B1B 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) | #484019 | 0.186 |
| Deuteranopia (no green cones) | #695D14 | 0.168 |
| Tritanopia (no blue cones) | #B4001E | 0.035 |
| Achromatopsia (no color) | #535353 | 0.172 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #A31B1B
#A31B1B
oklch(46.3% 0.171 27.2)
- #00656F
#00656F
oklch(46.3% 0.079 206.6)
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 #A31B1B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Auburn #9B2226 ΔE 0.018
- Burnt Red #9F2305 ΔE 0.020
- Brown #A52A2A ΔE 0.022
- Carmine #9D0216 ΔE 0.025
- Rufous #AE2012 ΔE 0.027
- Rust Red #AA2704 ΔE 0.029
- Deep Red #9A0200 ΔE 0.032
- Firebrick #B22222 ΔE 0.035
Use #A31B1B 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.