#B10C37
Closest named color: Rouge (#AB1239). oklch(48.6% 0.189 16.7), rgb(177, 12, 55).
Aa
White text reads best on this color (7.05:1).
About this color
#B10C37 is a medium-dark, vivid red. In OKLCH its lightness is 49%, its chroma 0.189 and its hue 17°. Its hue sits on the warm side of the wheel. The nearest named color is Rouge (#AB1239), ΔE 0.012 away. White text reads best on it, at 7.05:1.
| Hue family | Reds |
| Lightness | medium-dark (49%) |
| Chroma | vivid (0.189) |
| Temperature | warm |
| Nearest name | Rouge (#AB1239) |
| Black text | 2.97:1 |
| White text | 7.05:1 |
Values
| HEX | #B10C37 |
| RGB | rgb(177, 12, 55) |
| HSL | hsl(344, 87%, 37%) |
| OKLCH | oklch(48.6% 0.189 16.7) |
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 #B10C37 | 7.05:1 | AAA | Lc -87.3 | Fine for body text |
| Black text on #B10C37 | 2.97:1 | Fails | Lc 21.8 | Dividers and decoration only |
| #B10C37 text on white | 7.05:1 | AAA | Lc 82.3 | Fine for body text |
| #B10C37 text on black | 2.97:1 | Fails | Lc -19.6 | 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
#FEF2F2
oklch(97.1% 0.013 17.4)
-
Step 100
100
#FBE3E4
oklch(93.6% 0.026 14.7)
-
Step 200
200
#F9CCCD
oklch(88.4% 0.051 16.7)
-
Step 300
300
#F6A9AC
oklch(81% 0.091 16.7)
-
Step 400
400
#ED7780
oklch(70.7% 0.146 16.8)
-
Step 500
500
#E44C60
oklch(63.2% 0.187 16.8)
-
Step 600
600
#CF2347
oklch(55.6% 0.203 16.7)
-
Step 700
700 (this color)
#B10C37
oklch(48.6% 0.189 16.7)
-
Step 800
800
#91152F
oklch(42.7% 0.156 16.7)
-
Step 900
900
#751C2A
oklch(37.8% 0.122 16.6)
-
Step 950
950
#451219
oklch(27% 0.078 16.1)
#B10C37 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) | #474437 | 0.212 |
| Deuteranopia (no green cones) | #6E6432 | 0.193 |
| Tritanopia (no blue cones) | #C30022 | 0.043 |
| Achromatopsia (no color) | #595959 | 0.191 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B10C37
#B10C37
oklch(48.6% 0.189 16.7)
- #006D6F
#006D6F
oklch(48.5% 0.083 197)
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 #B10C37, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rouge #AB1239 ΔE 0.012
- Rose Red #BE013C ΔE 0.027
- Raspberry #B00149 ΔE 0.028
- Lipstick Red #C0022F ΔE 0.032
- Firebrick #B22222 ΔE 0.035
- Scarlet #BE0119 ΔE 0.040
- Brown #A52A2A ΔE 0.040
- Rufous #AE2012 ΔE 0.044
Use #B10C37 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.