#B73B21
Closest named color: Sinopia (#BB3E03). oklch(52.9% 0.165 33.5), rgb(183, 59, 33).
Aa
White text reads best on this color (5.73:1).
About this color
#B73B21 is a medium-dark, vivid red. In OKLCH its lightness is 53%, its chroma 0.165 and its hue 34°. Its hue sits on the warm side of the wheel. The nearest named color is Sinopia (#BB3E03), ΔE 0.019 away. White text reads best on it, at 5.73:1.
| Hue family | Reds |
| Lightness | medium-dark (53%) |
| Chroma | vivid (0.165) |
| Temperature | warm |
| Nearest name | Sinopia (#BB3E03) |
| Black text | 3.66:1 |
| White text | 5.73:1 |
Values
| HEX | #B73B21 |
| RGB | rgb(183, 59, 33) |
| HSL | hsl(10, 69%, 42%) |
| OKLCH | oklch(52.9% 0.165 33.5) |
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 #B73B21 | 5.73:1 | AA | Lc -82.9 | Fine for body text |
| Black text on #B73B21 | 3.66:1 | AA large text | Lc 26.5 | Dividers and decoration only |
| #B73B21 text on white | 5.73:1 | AA | Lc 77.6 | Fine for body text |
| #B73B21 text on black | 3.66:1 | AA large text | Lc -24.1 | 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
#FCF3F1
oklch(97.1% 0.01 32.5)
-
Step 100
100
#F8E5E1
oklch(93.6% 0.022 31.8)
-
Step 200
200
#F3D0C8
oklch(88.5% 0.041 33)
-
Step 300
300
#ECB0A2
oklch(80.9% 0.073 33.5)
-
Step 400
400
#E0846F
oklch(70.7% 0.118 33.7)
-
Step 500
500
#D56149
oklch(63.1% 0.152 33.2)
-
Step 600
600 (this color)
#B73B21
oklch(52.9% 0.165 33.5)
-
Step 700
700
#A6341D
oklch(49.1% 0.154 33.2)
-
Step 800
800
#862D1A
oklch(42.7% 0.126 33.7)
-
Step 900
900
#6C291B
oklch(37.6% 0.099 33.5)
-
Step 950
950
#401911
oklch(27% 0.063 33.1)
#B73B21 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) | #5F551D | 0.171 |
| Deuteranopia (no green cones) | #7E701B | 0.155 |
| Tritanopia (no blue cones) | #CA1136 | 0.062 |
| Achromatopsia (no color) | #666666 | 0.166 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B73B21
#B73B21
oklch(52.9% 0.165 33.5)
- #00798C
#00798C
oklch(53% 0.093 213.6)
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 #B73B21, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sinopia #BB3E03 ΔE 0.019
- Rusty Red #AF2F0D ΔE 0.029
- Dull Red #BB3F3F ΔE 0.031
- Firebrick #B22222 ΔE 0.041
- Brick Orange #C14A09 ΔE 0.042
- Rust Red #AA2704 ΔE 0.046
- Rufous #AE2012 ΔE 0.046
- Dusty Red #B9484E ΔE 0.048
Use #B73B21 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.