#B10B00
Closest named color: Rufous (#AE2012). oklch(48.1% 0.193 30), rgb(177, 11, 0).
Aa
White text reads best on this color (7.19:1).
About this color
#B10B00 is a medium-dark, vivid red. In OKLCH its lightness is 48%, its chroma 0.193 and its hue 30°. Its hue sits on the warm side of the wheel. The nearest named color is Rufous (#AE2012), ΔE 0.015 away. White text reads best on it, at 7.19:1.
| Hue family | Reds |
| Lightness | medium-dark (48%) |
| Chroma | vivid (0.193) |
| Temperature | warm |
| Nearest name | Rufous (#AE2012) |
| Black text | 2.91:1 |
| White text | 7.19:1 |
Values
| HEX | #B10B00 |
| RGB | rgb(177, 11, 0) |
| HSL | hsl(4, 100%, 35%) |
| OKLCH | oklch(48.1% 0.193 30) |
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 #B10B00 | 7.19:1 | AAA | Lc -87.7 | Fine for body text |
| Black text on #B10B00 | 2.91:1 | Fails | Lc 21.4 | Dividers and decoration only |
| #B10B00 text on white | 7.19:1 | AAA | Lc 82.6 | Fine for body text |
| #B10B00 text on black | 2.91:1 | Fails | Lc -19.3 | 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
#FEF3F0
oklch(97.2% 0.013 35.7)
-
Step 100
100
#FCE4DF
oklch(93.7% 0.027 31.7)
-
Step 200
200
#FACDC5
oklch(88.5% 0.052 29.9)
-
Step 300
300
#F7AA9D
oklch(80.9% 0.093 29.9)
-
Step 400
400
#EF7967
oklch(70.8% 0.149 30.2)
-
Step 500
500
#E64E3C
oklch(63.1% 0.191 30)
-
Step 600
600
#D12616
oklch(55.6% 0.207 30.1)
-
Step 700
700 (this color)
#B10B00
oklch(48.1% 0.193 30)
-
Step 800
800
#93170C
oklch(42.8% 0.16 30)
-
Step 900
900
#761D14
oklch(37.8% 0.125 29.8)
-
Step 950
950
#45130D
oklch(26.9% 0.078 29.9)
#B10B00 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) | #4B4100 | 0.210 |
| Deuteranopia (no green cones) | #716300 | 0.185 |
| Tritanopia (no blue cones) | #C4000E | 0.040 |
| Achromatopsia (no color) | #575757 | 0.194 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B10B00
#B10B00
oklch(48.1% 0.193 30)
- #006A78
#006A78
oklch(48.1% 0.083 210.5)
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 #B10B00, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rufous #AE2012 ΔE 0.015
- Firebrick #B22222 ΔE 0.023
- Rust Red #AA2704 ΔE 0.025
- Scarlet #BE0119 ΔE 0.030
- Rusty Red #AF2F0D ΔE 0.034
- Brown #A52A2A ΔE 0.036
- Burnt Red #9F2305 ΔE 0.037
- Lipstick Red #C0022F ΔE 0.046
Use #B10B00 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.