#B51918
Closest named color: Firebrick (#B22222). oklch(49.6% 0.189 27.9), rgb(181, 25, 24).
Aa
White text reads best on this color (6.73:1).
About this color
#B51918 is a medium-dark, vivid red. In OKLCH its lightness is 50%, its chroma 0.189 and its hue 28°. Its hue sits on the warm side of the wheel. The nearest named color is Firebrick (#B22222), ΔE 0.010 away. White text reads best on it, at 6.73:1.
| Hue family | Reds |
| Lightness | medium-dark (50%) |
| Chroma | vivid (0.189) |
| Temperature | warm |
| Nearest name | Firebrick (#B22222) |
| Black text | 3.11:1 |
| White text | 6.73:1 |
Values
| HEX | #B51918 |
| RGB | rgb(181, 25, 24) |
| HSL | hsl(0, 77%, 40%) |
| OKLCH | oklch(49.6% 0.189 27.9) |
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 #B51918 | 6.73:1 | AA | Lc -86.4 | Fine for body text |
| Black text on #B51918 | 3.11:1 | AA large text | Lc 22.8 | Dividers and decoration only |
| #B51918 text on white | 6.73:1 | AA | Lc 81.3 | Fine for body text |
| #B51918 text on black | 3.11:1 | AA large text | Lc -20.6 | 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
#FEF3F1
oklch(97.2% 0.012 29.9)
-
Step 100
100
#FBE4E0
oklch(93.6% 0.026 29.4)
-
Step 200
200
#F9CDC7
oklch(88.5% 0.051 27.2)
-
Step 300
300
#F6AAA0
oklch(80.8% 0.091 27.6)
-
Step 400
400
#EE796C
oklch(70.7% 0.147 27.9)
-
Step 500
500
#E44F44
oklch(63% 0.187 27.9)
-
Step 600
600
#D02824
oklch(55.6% 0.203 27.9)
-
Step 700
700 (this color)
#B51918
oklch(49.6% 0.189 27.9)
-
Step 800
800
#921916
oklch(42.8% 0.156 27.9)
-
Step 900
900
#751E19
oklch(37.7% 0.122 27.8)
-
Step 950
950
#45130F
oklch(26.9% 0.078 28)
#B51918 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) | #4F4615 | 0.206 |
| Deuteranopia (no green cones) | #74670C | 0.186 |
| Tritanopia (no blue cones) | #C8001C | 0.038 |
| Achromatopsia (no color) | #5C5C5C | 0.190 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B51918
#B51918
oklch(49.6% 0.189 27.9)
- #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 #B51918, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Firebrick #B22222 ΔE 0.010
- Rufous #AE2012 ΔE 0.015
- Scarlet #BE0119 ΔE 0.019
- Rust Red #AA2704 ΔE 0.028
- Rusty Red #AF2F0D ΔE 0.029
- Lipstick Red #C0022F ΔE 0.034
- Brown #A52A2A ΔE 0.034
- Rouge #AB1239 ΔE 0.044
Use #B51918 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.