#B03310
Closest named color: Rusty Red (#AF2F0D). oklch(50.7% 0.167 35.1), rgb(176, 51, 16).
Aa
White text reads best on this color (6.31:1).
About this color
#B03310 is a medium-dark, vivid red. In OKLCH its lightness is 51%, its chroma 0.167 and its hue 35°. Its hue sits on the warm side of the wheel. The nearest named color is Rusty Red (#AF2F0D), ΔE 0.007 away. White text reads best on it, at 6.31:1.
| Hue family | Reds |
| Lightness | medium-dark (51%) |
| Chroma | vivid (0.167) |
| Temperature | warm |
| Nearest name | Rusty Red (#AF2F0D) |
| Black text | 3.32:1 |
| White text | 6.31:1 |
Values
| HEX | #B03310 |
| RGB | rgb(176, 51, 16) |
| HSL | hsl(13, 83%, 38%) |
| OKLCH | oklch(50.7% 0.167 35.1) |
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 #B03310 | 6.31:1 | AA | Lc -85.4 | Fine for body text |
| Black text on #B03310 | 3.32:1 | AA large text | Lc 23.9 | Dividers and decoration only |
| #B03310 text on white | 6.31:1 | AA | Lc 80.2 | Fine for body text |
| #B03310 text on black | 3.32:1 | AA large text | Lc -21.6 | 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
#FDF3F1
oklch(97.1% 0.011 31.1)
-
Step 100
100
#F9E5DF
oklch(93.6% 0.023 37.4)
-
Step 200
200
#F5CFC5
oklch(88.4% 0.045 35.1)
-
Step 300
300
#F0AE9D
oklch(80.8% 0.082 35)
-
Step 400
400
#E58168
oklch(70.7% 0.129 35)
-
Step 500
500
#DA5C3D
oklch(63% 0.165 35)
-
Step 600
600
#C63D18
oklch(55.6% 0.18 35.1)
-
Step 700
700 (this color)
#B03310
oklch(50.7% 0.167 35.1)
-
Step 800
800
#8A280D
oklch(42.7% 0.138 35.2)
-
Step 900
900
#6F2614
oklch(37.6% 0.108 35)
-
Step 950
950
#42180D
oklch(27.1% 0.068 35.7)
#B03310 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) | #594E07 | 0.173 |
| Deuteranopia (no green cones) | #786A04 | 0.156 |
| Tritanopia (no blue cones) | #C2002D | 0.061 |
| Achromatopsia (no color) | #606060 | 0.168 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B03310
#B03310
oklch(50.7% 0.167 35.1)
- #007285
#007285
oklch(50.8% 0.09 214.5)
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 #B03310, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rusty Red #AF2F0D ΔE 0.007
- Rust Red #AA2704 ΔE 0.024
- Rufous #AE2012 ΔE 0.028
- Firebrick #B22222 ΔE 0.030
- Russet #A13905 ΔE 0.031
- Brick #A03623 ΔE 0.033
- Sinopia #BB3E03 ΔE 0.033
- Brown #A52A2A ΔE 0.039
Use #B03310 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.