#AC1821
Closest named color: Rufous (#AE2012). oklch(47.9% 0.18 25.2), rgb(172, 24, 33).
Aa
White text reads best on this color (7.22:1).
About this color
#AC1821 is a medium-dark, vivid red. In OKLCH its lightness is 48%, its chroma 0.180 and its hue 25°. Its hue sits on the warm side of the wheel. The nearest named color is Rufous (#AE2012), ΔE 0.017 away. White text reads best on it, at 7.22:1.
| Hue family | Reds |
| Lightness | medium-dark (48%) |
| Chroma | vivid (0.180) |
| Temperature | warm |
| Nearest name | Rufous (#AE2012) |
| Black text | 2.90:1 |
| White text | 7.22:1 |
Values
| HEX | #AC1821 |
| RGB | rgb(172, 24, 33) |
| HSL | hsl(356, 76%, 38%) |
| OKLCH | oklch(47.9% 0.18 25.2) |
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 #AC1821 | 7.22:1 | AAA | Lc -88.2 | Fine for body text |
| Black text on #AC1821 | 2.90:1 | Fails | Lc 20.8 | Dividers and decoration only |
| #AC1821 text on white | 7.22:1 | AAA | Lc 83.2 | Fine for body text |
| #AC1821 text on black | 2.90:1 | Fails | Lc -18.7 | 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
#FDF3F1
oklch(97.1% 0.011 31.1)
-
Step 100
100
#FBE4E1
oklch(93.7% 0.026 26.5)
-
Step 200
200
#F8CEC9
oklch(88.6% 0.048 26)
-
Step 300
300
#F4ABA4
oklch(80.9% 0.087 25.3)
-
Step 400
400
#EB7B73
oklch(70.8% 0.14 25.4)
-
Step 500
500
#E1534F
oklch(63.2% 0.178 25.2)
-
Step 600
600
#CC2E32
oklch(55.5% 0.194 25.2)
-
Step 700
700 (this color)
#AC1821
oklch(47.9% 0.18 25.2)
-
Step 800
800
#8F1D20
oklch(42.7% 0.149 25.1)
-
Step 900
900
#73201F
oklch(37.7% 0.117 25.3)
-
Step 950
950
#441413
oklch(27% 0.075 24.6)
#AC1821 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) | #4A431F | 0.199 |
| Deuteranopia (no green cones) | #6E621A | 0.179 |
| Tritanopia (no blue cones) | #BE001E | 0.036 |
| Achromatopsia (no color) | #575757 | 0.182 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #AC1821
#AC1821
oklch(47.9% 0.18 25.2)
- #006A73
#006A73
oklch(47.8% 0.082 205)
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 #AC1821, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rufous #AE2012 ΔE 0.017
- Firebrick #B22222 ΔE 0.019
- Brown #A52A2A ΔE 0.021
- Rust Red #AA2704 ΔE 0.028
- Rouge #AB1239 ΔE 0.030
- Auburn #9B2226 ΔE 0.034
- Burnt Red #9F2305 ΔE 0.035
- Scarlet #BE0119 ΔE 0.036
Use #AC1821 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.