#B31D1A
Closest named color: Firebrick (#B22222). oklch(49.5% 0.185 28), rgb(179, 29, 26).
Aa
White text reads best on this color (6.75:1).
About this color
#B31D1A is a medium-dark, vivid red. In OKLCH its lightness is 49%, its chroma 0.185 and its hue 28°. Its hue sits on the warm side of the wheel. The nearest named color is Firebrick (#B22222), ΔE 0.007 away. White text reads best on it, at 6.75:1.
| Hue family | Reds |
| Lightness | medium-dark (49%) |
| Chroma | vivid (0.185) |
| Temperature | warm |
| Nearest name | Firebrick (#B22222) |
| Black text | 3.10:1 |
| White text | 6.75:1 |
Values
| HEX | #B31D1A |
| RGB | rgb(179, 29, 26) |
| HSL | hsl(1, 75%, 40%) |
| OKLCH | oklch(49.5% 0.185 28) |
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 #B31D1A | 6.75:1 | AA | Lc -86.6 | Fine for body text |
| Black text on #B31D1A | 3.10:1 | AA large text | Lc 22.6 | Dividers and decoration only |
| #B31D1A text on white | 6.75:1 | AA | Lc 81.5 | Fine for body text |
| #B31D1A text on black | 3.10:1 | AA large text | Lc -20.4 | 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
#FBE4E0
oklch(93.6% 0.026 29.4)
-
Step 200
200
#F8CDC7
oklch(88.4% 0.05 27.4)
-
Step 300
300
#F5ABA0
oklch(80.9% 0.089 28.6)
-
Step 400
400
#EC7A6D
oklch(70.6% 0.143 28)
-
Step 500
500
#E35146
oklch(63.1% 0.184 27.8)
-
Step 600
600
#CE2C26
oklch(55.6% 0.199 28.1)
-
Step 700
700 (this color)
#B31D1A
oklch(49.5% 0.185 28)
-
Step 800
800
#901B17
oklch(42.6% 0.153 28)
-
Step 900
900
#741F1A
oklch(37.7% 0.12 27.7)
-
Step 950
950
#441410
oklch(26.9% 0.075 27.9)
#B31D1A 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) | #504717 | 0.200 |
| Deuteranopia (no green cones) | #746710 | 0.182 |
| Tritanopia (no blue cones) | #C6001F | 0.039 |
| Achromatopsia (no color) | #5B5B5B | 0.186 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B31D1A
#B31D1A
oklch(49.5% 0.185 28)
- #006F7B
#006F7B
oklch(49.5% 0.085 207.8)
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 #B31D1A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Firebrick #B22222 ΔE 0.007
- Rufous #AE2012 ΔE 0.012
- Scarlet #BE0119 ΔE 0.024
- Rust Red #AA2704 ΔE 0.025
- Rusty Red #AF2F0D ΔE 0.026
- Brown #A52A2A ΔE 0.030
- Lipstick Red #C0022F ΔE 0.036
- Rouge #AB1239 ΔE 0.043
Use #B31D1A 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.