#B31730
Closest named color: Firebrick (#B22222). oklch(49.4% 0.186 20.6), rgb(179, 23, 48).
Aa
White text reads best on this color (6.81:1).
About this color
#B31730 is a medium-dark, vivid red. In OKLCH its lightness is 49%, its chroma 0.186 and its hue 21°. Its hue sits on the warm side of the wheel. The nearest named color is Firebrick (#B22222), ΔE 0.021 away. White text reads best on it, at 6.81:1.
| Hue family | Reds |
| Lightness | medium-dark (49%) |
| Chroma | vivid (0.186) |
| Temperature | warm |
| Nearest name | Firebrick (#B22222) |
| Black text | 3.08:1 |
| White text | 6.81:1 |
Values
| HEX | #B31730 |
| RGB | rgb(179, 23, 48) |
| HSL | hsl(350, 77%, 40%) |
| OKLCH | oklch(49.4% 0.186 20.6) |
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 #B31730 | 6.81:1 | AA | Lc -86.7 | Fine for body text |
| Black text on #B31730 | 3.08:1 | AA large text | Lc 22.5 | Dividers and decoration only |
| #B31730 text on white | 6.81:1 | AA | Lc 81.6 | Fine for body text |
| #B31730 text on black | 3.08:1 | AA large text | Lc -20.3 | 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
#FEF2F2
oklch(97.1% 0.013 17.4)
-
Step 100
100
#FBE3E2
oklch(93.5% 0.026 20.5)
-
Step 200
200
#F9CDCB
oklch(88.6% 0.05 21.2)
-
Step 300
300
#F5AAA8
oklch(80.9% 0.089 20.9)
-
Step 400
400
#ED787A
oklch(70.7% 0.145 20.4)
-
Step 500
500
#E34E58
oklch(63.1% 0.184 20.4)
-
Step 600
600
#CE273D
oklch(55.5% 0.2 20.6)
-
Step 700
700 (this color)
#B31730
oklch(49.4% 0.186 20.6)
-
Step 800
800
#911828
oklch(42.8% 0.154 20.6)
-
Step 900
900
#741D25
oklch(37.6% 0.12 20.2)
-
Step 950
950
#441316
oklch(26.9% 0.075 20.3)
#B31730 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) | #4C462F | 0.206 |
| Deuteranopia (no green cones) | #71662B | 0.188 |
| Tritanopia (no blue cones) | #C50023 | 0.037 |
| Achromatopsia (no color) | #5B5B5B | 0.187 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B31730
#B31730
oklch(49.4% 0.186 20.6)
- #006F75
#006F75
oklch(49.3% 0.084 201.4)
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 #B31730, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Firebrick #B22222 ΔE 0.021
- Rouge #AB1239 ΔE 0.023
- Lipstick Red #C0022F ΔE 0.026
- Rose Red #BE013C ΔE 0.028
- Scarlet #BE0119 ΔE 0.028
- Rufous #AE2012 ΔE 0.032
- Brown #A52A2A ΔE 0.033
- Raspberry #B00149 ΔE 0.042
Use #B31730 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.