#B31B38
Closest named color: Rouge (#AB1239). oklch(49.7% 0.184 18.1), rgb(179, 27, 56).
Aa
White text reads best on this color (6.70:1).
About this color
#B31B38 is a medium-dark, vivid red. In OKLCH its lightness is 50%, its chroma 0.184 and its hue 18°. Its hue sits on the warm side of the wheel. The nearest named color is Rouge (#AB1239), ΔE 0.021 away. White text reads best on it, at 6.70:1.
| Hue family | Reds |
| Lightness | medium-dark (50%) |
| Chroma | vivid (0.184) |
| Temperature | warm |
| Nearest name | Rouge (#AB1239) |
| Black text | 3.13:1 |
| White text | 6.70:1 |
Values
| HEX | #B31B38 |
| RGB | rgb(179, 27, 56) |
| HSL | hsl(349, 74%, 40%) |
| OKLCH | oklch(49.7% 0.184 18.1) |
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 #B31B38 | 6.70:1 | AA | Lc -86.4 | Fine for body text |
| Black text on #B31B38 | 3.13:1 | AA large text | Lc 22.8 | Dividers and decoration only |
| #B31B38 text on white | 6.70:1 | AA | Lc 81.3 | Fine for body text |
| #B31B38 text on black | 3.13:1 | 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
#FDF2F2
oklch(97% 0.012 17.4)
-
Step 100
100
#FBE3E3
oklch(93.5% 0.026 17.6)
-
Step 200
200
#F8CDCD
oklch(88.5% 0.049 18.1)
-
Step 300
300
#F5AAAB
oklch(81% 0.089 18.3)
-
Step 400
400
#EC787E
oklch(70.7% 0.143 18.2)
-
Step 500
500
#E24F5E
oklch(63.1% 0.182 18.2)
-
Step 600
600
#CD2945
oklch(55.6% 0.197 18)
-
Step 700
700 (this color)
#B31B38
oklch(49.7% 0.184 18.1)
-
Step 800
800
#90192D
oklch(42.8% 0.153 18.3)
-
Step 900
900
#731E29
oklch(37.6% 0.118 17.7)
-
Step 950
950
#441318
oklch(26.9% 0.075 17.8)
#B31B38 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) | #4C4838 | 0.204 |
| Deuteranopia (no green cones) | #716733 | 0.187 |
| Tritanopia (no blue cones) | #C50029 | 0.038 |
| Achromatopsia (no color) | #5C5C5C | 0.185 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B31B38
#B31B38
oklch(49.7% 0.184 18.1)
- #007174
#007174
oklch(49.8% 0.085 198)
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 #B31B38, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rouge #AB1239 ΔE 0.021
- Rose Red #BE013C ΔE 0.024
- Lipstick Red #C0022F ΔE 0.027
- Firebrick #B22222 ΔE 0.028
- Scarlet #BE0119 ΔE 0.035
- Raspberry #B00149 ΔE 0.036
- Brown #A52A2A ΔE 0.037
- Rufous #AE2012 ΔE 0.040
Use #B31B38 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.