#B51D33
Closest named color: Firebrick (#B22222). oklch(50.1% 0.184 20.5), rgb(181, 29, 51).
Aa
White text reads best on this color (6.58:1).
About this color
#B51D33 is a medium-dark, vivid red. In OKLCH its lightness is 50%, its chroma 0.184 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 6.58:1.
| Hue family | Reds |
| Lightness | medium-dark (50%) |
| Chroma | vivid (0.184) |
| Temperature | warm |
| Nearest name | Firebrick (#B22222) |
| Black text | 3.18:1 |
| White text | 6.58:1 |
Values
| HEX | #B51D33 |
| RGB | rgb(181, 29, 51) |
| HSL | hsl(351, 72%, 41%) |
| OKLCH | oklch(50.1% 0.184 20.5) |
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 #B51D33 | 6.58:1 | AA | Lc -86.0 | Fine for body text |
| Black text on #B51D33 | 3.18:1 | AA large text | Lc 23.2 | Dividers and decoration only |
| #B51D33 text on white | 6.58:1 | AA | Lc 80.8 | Fine for body text |
| #B51D33 text on black | 3.18:1 | 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
#FDF2F2
oklch(97% 0.012 17.4)
-
Step 100
100
#FBE4E3
oklch(93.7% 0.025 20.6)
-
Step 200
200
#F8CDCB
oklch(88.5% 0.049 21.2)
-
Step 300
300
#F5AAA8
oklch(80.9% 0.089 20.9)
-
Step 400
400
#EC797A
oklch(70.7% 0.142 20.8)
-
Step 500
500
#E24F58
oklch(63% 0.182 20.6)
-
Step 600
600
#CE293E
oklch(55.7% 0.199 20.6)
-
Step 700
700 (this color)
#B51D33
oklch(50.1% 0.184 20.5)
-
Step 800
800
#901929
oklch(42.7% 0.153 20.3)
-
Step 900
900
#741E25
oklch(37.7% 0.119 20.6)
-
Step 950
950
#441316
oklch(26.9% 0.075 20.3)
#B51D33 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) | #4E4932 | 0.204 |
| Deuteranopia (no green cones) | #73682E | 0.186 |
| Tritanopia (no blue cones) | #C70027 | 0.036 |
| Achromatopsia (no color) | #5D5D5D | 0.186 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B51D33
#B51D33
oklch(50.1% 0.184 20.5)
- #007277
#007277
oklch(50.2% 0.085 200.1)
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 #B51D33, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Firebrick #B22222 ΔE 0.021
- Lipstick Red #C0022F ΔE 0.023
- Rose Red #BE013C ΔE 0.026
- Scarlet #BE0119 ΔE 0.028
- Rouge #AB1239 ΔE 0.029
- Rufous #AE2012 ΔE 0.034
- Brown #A52A2A ΔE 0.035
- Raspberry #B00149 ΔE 0.044
Use #B51D33 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.