#B51B37
Closest named color: Rose Red (#BE013C). oklch(50.1% 0.185 18.7), rgb(181, 27, 55).
Aa
White text reads best on this color (6.61:1).
About this color
#B51B37 is a medium-dark, vivid red. In OKLCH its lightness is 50%, its chroma 0.185 and its hue 19°. Its hue sits on the warm side of the wheel. The nearest named color is Rose Red (#BE013C), ΔE 0.022 away. White text reads best on it, at 6.61:1.
| Hue family | Reds |
| Lightness | medium-dark (50%) |
| Chroma | vivid (0.185) |
| Temperature | warm |
| Nearest name | Rose Red (#BE013C) |
| Black text | 3.17:1 |
| White text | 6.61:1 |
Values
| HEX | #B51B37 |
| RGB | rgb(181, 27, 55) |
| HSL | hsl(349, 74%, 41%) |
| OKLCH | oklch(50.1% 0.185 18.7) |
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 #B51B37 | 6.61:1 | AA | Lc -86.0 | Fine for body text |
| Black text on #B51B37 | 3.17:1 | AA large text | Lc 23.2 | Dividers and decoration only |
| #B51B37 text on white | 6.61:1 | AA | Lc 80.9 | Fine for body text |
| #B51B37 text on black | 3.17:1 | AA large text | Lc -21.0 | 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
#FEF2F2
oklch(97.1% 0.013 17.4)
-
Step 100
100
#FBE3E3
oklch(93.5% 0.026 17.6)
-
Step 200
200
#F9CDCC
oklch(88.6% 0.05 19.7)
-
Step 300
300
#F5A9AA
oklch(80.8% 0.09 18.4)
-
Step 400
400
#EC787D
oklch(70.7% 0.143 18.7)
-
Step 500
500
#E34E5C
oklch(63.1% 0.184 18.8)
-
Step 600
600
#CE2742
oklch(55.6% 0.2 18.9)
-
Step 700
700 (this color)
#B51B37
oklch(50.1% 0.185 18.7)
-
Step 800
800
#90182C
oklch(42.7% 0.153 18.6)
-
Step 900
900
#741D27
oklch(37.7% 0.12 18.9)
-
Step 950
950
#441317
oklch(26.9% 0.075 19)
#B51B37 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) | #4D4837 | 0.206 |
| Deuteranopia (no green cones) | #736832 | 0.187 |
| Tritanopia (no blue cones) | #C70028 | 0.037 |
| Achromatopsia (no color) | #5D5D5D | 0.187 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B51B37
#B51B37
oklch(50.1% 0.185 18.7)
- #007276
#007276
oklch(50.1% 0.085 199.1)
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 #B51B37, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rose Red #BE013C ΔE 0.022
- Lipstick Red #C0022F ΔE 0.023
- Rouge #AB1239 ΔE 0.026
- Firebrick #B22222 ΔE 0.027
- Scarlet #BE0119 ΔE 0.032
- Raspberry #B00149 ΔE 0.039
- Brown #A52A2A ΔE 0.039
- Rufous #AE2012 ΔE 0.040
Use #B51B37 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.