#AC370E
Closest named color: Rusty Red (#AF2F0D). oklch(50.4% 0.16 37.1), rgb(172, 55, 14).
Aa
White text reads best on this color (6.35:1).
About this color
#AC370E is a medium-dark, vivid red. In OKLCH its lightness is 50%, its chroma 0.160 and its hue 37°. Its hue sits on the warm side of the wheel. The nearest named color is Rusty Red (#AF2F0D), ΔE 0.013 away. White text reads best on it, at 6.35:1.
| Hue family | Reds |
| Lightness | medium-dark (50%) |
| Chroma | vivid (0.160) |
| Temperature | warm |
| Nearest name | Rusty Red (#AF2F0D) |
| Black text | 3.30:1 |
| White text | 6.35:1 |
Values
| HEX | #AC370E |
| RGB | rgb(172, 55, 14) |
| HSL | hsl(16, 85%, 36%) |
| OKLCH | oklch(50.4% 0.16 37.1) |
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 #AC370E | 6.35:1 | AA | Lc -85.7 | Fine for body text |
| Black text on #AC370E | 3.30:1 | AA large text | Lc 23.6 | Dividers and decoration only |
| #AC370E text on white | 6.35:1 | AA | Lc 80.5 | Fine for body text |
| #AC370E text on black | 3.30:1 | AA large text | Lc -21.4 | 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
#FCF3F1
oklch(97.1% 0.01 32.5)
-
Step 100
100
#F8E5DF
oklch(93.5% 0.022 38.3)
-
Step 200
200
#F4D0C5
oklch(88.5% 0.043 37.7)
-
Step 300
300
#EEB09D
oklch(81% 0.078 37.7)
-
Step 400
400
#E28368
oklch(70.7% 0.124 36.7)
-
Step 500
500
#D7603D
oklch(63.1% 0.158 37)
-
Step 600
600
#C24217
oklch(55.5% 0.172 37.2)
-
Step 700
700 (this color)
#AC370E
oklch(50.4% 0.16 37.1)
-
Step 800
800
#882B0C
oklch(42.6% 0.133 37)
-
Step 900
900
#6D2914
oklch(37.7% 0.102 37.4)
-
Step 950
950
#40190D
oklch(27% 0.065 37.7)
#AC370E 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) | #5A4F04 | 0.163 |
| Deuteranopia (no green cones) | #776903 | 0.147 |
| Tritanopia (no blue cones) | #BE0D30 | 0.065 |
| Achromatopsia (no color) | #5F5F5F | 0.161 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #AC370E
#AC370E
oklch(50.4% 0.16 37.1)
- #007086
#007086
oklch(50.3% 0.09 217.7)
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 #AC370E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rusty Red #AF2F0D ΔE 0.013
- Russet #A13905 ΔE 0.023
- Rust Red #AA2704 ΔE 0.025
- Brick #A03623 ΔE 0.028
- Burnt Umber #A0450E ΔE 0.033
- Rufous #AE2012 ΔE 0.033
- Sinopia #BB3E03 ΔE 0.036
- Firebrick #B22222 ΔE 0.037
Use #AC370E 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.