#B40737
Closest named color: Rouge (#AB1239). oklch(49.1% 0.193 16.8), rgb(180, 7, 55).
Aa
White text reads best on this color (6.93:1).
About this color
#B40737 is a medium-dark, vivid red. In OKLCH its lightness is 49%, its chroma 0.193 and its hue 17°. Its hue sits on the warm side of the wheel. The nearest named color is Rouge (#AB1239), ΔE 0.018 away. White text reads best on it, at 6.93:1.
| Hue family | Reds |
| Lightness | medium-dark (49%) |
| Chroma | vivid (0.193) |
| Temperature | warm |
| Nearest name | Rouge (#AB1239) |
| Black text | 3.02:1 |
| White text | 6.93:1 |
Values
| HEX | #B40737 |
| RGB | rgb(180, 7, 55) |
| HSL | hsl(343, 93%, 37%) |
| OKLCH | oklch(49.1% 0.193 16.8) |
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 #B40737 | 6.93:1 | AA | Lc -86.8 | Fine for body text |
| Black text on #B40737 | 3.02:1 | AA large text | Lc 22.4 | Dividers and decoration only |
| #B40737 text on white | 6.93:1 | AA | Lc 81.7 | Fine for body text |
| #B40737 text on black | 3.02:1 | AA large text | Lc -20.2 | 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
#FCE3E3
oklch(93.6% 0.028 17.7)
-
Step 200
200
#FACCCD
oklch(88.5% 0.052 16.7)
-
Step 300
300
#F7A8AB
oklch(80.9% 0.094 16.8)
-
Step 400
400
#EF757F
oklch(70.7% 0.15 16.6)
-
Step 500
500
#E54A5F
oklch(63.1% 0.19 16.8)
-
Step 600
600
#D11E45
oklch(55.7% 0.208 17)
-
Step 700
700 (this color)
#B40737
oklch(49.1% 0.193 16.8)
-
Step 800
800
#92112E
oklch(42.7% 0.16 16.7)
-
Step 900
900
#751A29
oklch(37.6% 0.124 16.6)
-
Step 950
950
#451218
oklch(27% 0.078 17.3)
#B40737 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) | #484437 | 0.216 |
| Deuteranopia (no green cones) | #706532 | 0.195 |
| Tritanopia (no blue cones) | #C60021 | 0.044 |
| Achromatopsia (no color) | #5A5A5A | 0.195 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B40737
#B40737
oklch(49.1% 0.193 16.8)
- #006F71
#006F71
oklch(49.1% 0.084 197)
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 #B40737, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rouge #AB1239 ΔE 0.018
- Rose Red #BE013C ΔE 0.021
- Lipstick Red #C0022F ΔE 0.027
- Raspberry #B00149 ΔE 0.029
- Firebrick #B22222 ΔE 0.036
- Scarlet #BE0119 ΔE 0.037
- Brown #A52A2A ΔE 0.044
- Rufous #AE2012 ΔE 0.046
Use #B40737 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.