#B63737
Closest named color: Dull Red (#BB3F3F). oklch(52.6% 0.164 24.8), rgb(182, 55, 55).
Aa
White text reads best on this color (5.84:1).
About this color
#B63737 is a medium-dark, vivid red. In OKLCH its lightness is 53%, its chroma 0.164 and its hue 25°. Its hue sits on the warm side of the wheel. The nearest named color is Dull Red (#BB3F3F), ΔE 0.019 away. White text reads best on it, at 5.84:1.
| Hue family | Reds |
| Lightness | medium-dark (53%) |
| Chroma | vivid (0.164) |
| Temperature | warm |
| Nearest name | Dull Red (#BB3F3F) |
| Black text | 3.59:1 |
| White text | 5.84:1 |
Values
| HEX | #B63737 |
| RGB | rgb(182, 55, 55) |
| HSL | hsl(0, 54%, 46%) |
| OKLCH | oklch(52.6% 0.164 24.8) |
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 #B63737 | 5.84:1 | AA | Lc -83.4 | Fine for body text |
| Black text on #B63737 | 3.59:1 | AA large text | Lc 25.9 | Dividers and decoration only |
| #B63737 text on white | 5.84:1 | AA | Lc 78.2 | Fine for body text |
| #B63737 text on black | 3.59:1 | AA large text | Lc -23.6 | 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 600.
-
Step 50
50
#FCF3F2
oklch(97.1% 0.01 25.1)
-
Step 100
100
#F8E5E3
oklch(93.7% 0.021 24.8)
-
Step 200
200
#F3CFCC
oklch(88.4% 0.041 23.6)
-
Step 300
300
#EDAFA9
oklch(81% 0.074 25.1)
-
Step 400
400
#E1827B
oklch(70.7% 0.118 25)
-
Step 500
500
#D55F5A
oklch(63.1% 0.15 24.7)
-
Step 600
600 (this color)
#B63737
oklch(52.6% 0.164 24.8)
-
Step 700
700
#A63232
oklch(49.2% 0.152 24.7)
-
Step 800
800
#872B2A
oklch(42.8% 0.126 24.7)
-
Step 900
900
#6C2826
oklch(37.6% 0.098 24.6)
-
Step 950
950
#401817
oklch(27% 0.063 23.6)
#B63737 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) | #5B5336 | 0.175 |
| Deuteranopia (no green cones) | #7A6F33 | 0.162 |
| Tritanopia (no blue cones) | #C80E39 | 0.048 |
| Achromatopsia (no color) | #656565 | 0.165 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B63737
#B63737
oklch(52.6% 0.164 24.8)
- #007983
#007983
oklch(52.6% 0.09 204.9)
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 #B63737, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dull Red #BB3F3F ΔE 0.019
- Firebrick #B22222 ΔE 0.034
- Dusty Red #B9484E ΔE 0.036
- Rusty Red #AF2F0D ΔE 0.038
- Sinopia #BB3E03 ΔE 0.044
- Rufous #AE2012 ΔE 0.045
- Brown #A52A2A ΔE 0.045
- Lipstick Red #C0022F ΔE 0.045
Use #B63737 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.