#B33437
Closest named color: Dull Red (#BB3F3F). oklch(51.7% 0.163 23.7), rgb(179, 52, 55).
Aa
White text reads best on this color (6.06:1).
About this color
#B33437 is a medium-dark, vivid red. In OKLCH its lightness is 52%, its chroma 0.163 and its hue 24°. Its hue sits on the warm side of the wheel. The nearest named color is Dull Red (#BB3F3F), ΔE 0.027 away. White text reads best on it, at 6.06:1.
| Hue family | Reds |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.163) |
| Temperature | warm |
| Nearest name | Dull Red (#BB3F3F) |
| Black text | 3.46:1 |
| White text | 6.06:1 |
Values
| HEX | #B33437 |
| RGB | rgb(179, 52, 55) |
| HSL | hsl(359, 55%, 45%) |
| OKLCH | oklch(51.7% 0.163 23.7) |
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 #B33437 | 6.06:1 | AA | Lc -84.4 | Fine for body text |
| Black text on #B33437 | 3.46:1 | AA large text | Lc 24.9 | Dividers and decoration only |
| #B33437 text on white | 6.06:1 | AA | Lc 79.2 | Fine for body text |
| #B33437 text on black | 3.46:1 | AA large text | Lc -22.7 | 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
#FDF3F2
oklch(97.2% 0.011 24.3)
-
Step 100
100
#F9E4E2
oklch(93.5% 0.023 24.1)
-
Step 200
200
#F5CFCB
oklch(88.6% 0.043 25.1)
-
Step 300
300
#F0ADA8
oklch(80.9% 0.08 23.8)
-
Step 400
400
#E57F7A
oklch(70.8% 0.127 23.7)
-
Step 500
500
#DA5A58
oklch(63.1% 0.162 23.8)
-
Step 600
600
#C53A3D
oklch(55.5% 0.176 23.9)
-
Step 700
700 (this color)
#B33437
oklch(51.7% 0.163 23.7)
-
Step 800
800
#8A2628
oklch(42.7% 0.135 23.9)
-
Step 900
900
#6F2525
oklch(37.7% 0.105 23.6)
-
Step 950
950
#411716
oklch(27% 0.066 23.9)
#B33437 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) | #585136 | 0.176 |
| Deuteranopia (no green cones) | #786C33 | 0.161 |
| Tritanopia (no blue cones) | #C50736 | 0.047 |
| Achromatopsia (no color) | #626262 | 0.165 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B33437
#B33437
oklch(51.7% 0.163 23.7)
- #00767F
#00767F
oklch(51.6% 0.088 204.1)
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 #B33437, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dull Red #BB3F3F ΔE 0.027
- Firebrick #B22222 ΔE 0.028
- Rusty Red #AF2F0D ΔE 0.036
- Brown #A52A2A ΔE 0.037
- Rufous #AE2012 ΔE 0.040
- Dusty Red #B9484E ΔE 0.043
- Lipstick Red #C0022F ΔE 0.043
- Scarlet #BE0119 ΔE 0.044
Use #B33437 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.