#B21723
Closest named color: Firebrick (#B22222). oklch(49% 0.186 24.8), rgb(178, 23, 35).
Aa
White text reads best on this color (6.90:1).
About this color
#B21723 is a medium-dark, vivid red. In OKLCH its lightness is 49%, its chroma 0.186 and its hue 25°. Its hue sits on the warm side of the wheel. The nearest named color is Firebrick (#B22222), ΔE 0.011 away. White text reads best on it, at 6.90:1.
| Hue family | Reds |
| Lightness | medium-dark (49%) |
| Chroma | vivid (0.186) |
| Temperature | warm |
| Nearest name | Firebrick (#B22222) |
| Black text | 3.03:1 |
| White text | 6.90:1 |
Values
| HEX | #B21723 |
| RGB | rgb(178, 23, 35) |
| HSL | hsl(355, 77%, 39%) |
| OKLCH | oklch(49% 0.186 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 #B21723 | 6.90:1 | AA | Lc -87.0 | Fine for body text |
| Black text on #B21723 | 3.03:1 | AA large text | Lc 22.1 | Dividers and decoration only |
| #B21723 text on white | 6.90:1 | AA | Lc 81.9 | Fine for body text |
| #B21723 text on black | 3.03:1 | AA large text | Lc -20.0 | 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
#FEF3F1
oklch(97.2% 0.012 29.9)
-
Step 100
100
#FBE4E1
oklch(93.7% 0.026 26.5)
-
Step 200
200
#F9CDC9
oklch(88.5% 0.05 24.2)
-
Step 300
300
#F6AAA3
oklch(80.9% 0.091 25.1)
-
Step 400
400
#ED7972
oklch(70.7% 0.144 24.9)
-
Step 500
500
#E3504D
oklch(63.1% 0.183 25.1)
-
Step 600
600
#CF2931
oklch(55.7% 0.2 24.7)
-
Step 700
700 (this color)
#B21723
oklch(49% 0.186 24.8)
-
Step 800
800
#91191F
oklch(42.7% 0.154 24.7)
-
Step 900
900
#741E1E
oklch(37.6% 0.12 25)
-
Step 950
950
#451312
oklch(27% 0.077 24.9)
#B21723 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) | #4D4521 | 0.204 |
| Deuteranopia (no green cones) | #72651C | 0.184 |
| Tritanopia (no blue cones) | #C5001E | 0.038 |
| Achromatopsia (no color) | #5A5A5A | 0.188 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #B21723
#B21723
oklch(49% 0.186 24.8)
- #006E77
#006E77
oklch(49.1% 0.084 204.7)
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 #B21723, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Firebrick #B22222 ΔE 0.011
- Rufous #AE2012 ΔE 0.019
- Scarlet #BE0119 ΔE 0.024
- Brown #A52A2A ΔE 0.028
- Lipstick Red #C0022F ΔE 0.032
- Rouge #AB1239 ΔE 0.032
- Rust Red #AA2704 ΔE 0.032
- Rusty Red #AF2F0D ΔE 0.036
Use #B21723 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.