#AD3731
Closest named color: Rusty Red (#AF2F0D). oklch(50.9% 0.155 27), rgb(173, 55, 49).
Aa
White text reads best on this color (6.23:1).
About this color
#AD3731 is a medium-dark, vivid red. In OKLCH its lightness is 51%, its chroma 0.155 and its hue 27°. Its hue sits on the warm side of the wheel. The nearest named color is Rusty Red (#AF2F0D), ΔE 0.027 away. White text reads best on it, at 6.23:1.
| Hue family | Reds |
| Lightness | medium-dark (51%) |
| Chroma | vivid (0.155) |
| Temperature | warm |
| Nearest name | Rusty Red (#AF2F0D) |
| Black text | 3.36:1 |
| White text | 6.23:1 |
Values
| HEX | #AD3731 |
| RGB | rgb(173, 55, 49) |
| HSL | hsl(3, 56%, 44%) |
| OKLCH | oklch(50.9% 0.155 27) |
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 #AD3731 | 6.23:1 | AA | Lc -85.2 | Fine for body text |
| Black text on #AD3731 | 3.36:1 | AA large text | Lc 24.0 | Dividers and decoration only |
| #AD3731 text on white | 6.23:1 | AA | Lc 80.1 | Fine for body text |
| #AD3731 text on black | 3.36:1 | AA large text | Lc -21.8 | 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
#FCF3F2
oklch(97.1% 0.01 25.1)
-
Step 100
100
#F8E5E2
oklch(93.6% 0.021 28.3)
-
Step 200
200
#F4CFCA
oklch(88.5% 0.042 27)
-
Step 300
300
#EDAFA7
oklch(81% 0.074 27.1)
-
Step 400
400
#E28277
oklch(70.8% 0.12 27.4)
-
Step 500
500
#D65E55
oklch(63% 0.153 26.7)
-
Step 600
600
#C24039
oklch(55.6% 0.167 27)
-
Step 700
700 (this color)
#AD3731
oklch(50.9% 0.155 27)
-
Step 800
800
#872A25
oklch(42.6% 0.128 27)
-
Step 900
900
#6D2823
oklch(37.7% 0.1 27)
-
Step 950
950
#401815
oklch(26.9% 0.063 26.5)
#AD3731 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) | #58502F | 0.165 |
| Deuteranopia (no green cones) | #756A2D | 0.152 |
| Tritanopia (no blue cones) | #BE1537 | 0.048 |
| Achromatopsia (no color) | #616161 | 0.156 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #AD3731
#AD3731
oklch(50.9% 0.155 27)
- #00747F
#00747F
oklch(51.1% 0.087 206.3)
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 #AD3731, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rusty Red #AF2F0D ΔE 0.027
- Firebrick #B22222 ΔE 0.028
- Brown #A52A2A ΔE 0.029
- Brick #A03623 ΔE 0.031
- Rufous #AE2012 ΔE 0.034
- Dull Red #BB3F3F ΔE 0.036
- Rust Red #AA2704 ΔE 0.036
- Russet #A13905 ΔE 0.043
Use #AD3731 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.