#643A37
Closest named color: Purple Brown (#673A3F). oklch(39.9% 0.06 24.5), rgb(100, 58, 55).
Aa
White text reads best on this color (9.53:1).
About this color
#643A37 is a dark, muted red. In OKLCH its lightness is 40%, its chroma 0.060 and its hue 25°. Its hue sits on the warm side of the wheel. The nearest named color is Purple Brown (#673A3F), ΔE 0.014 away. White text reads best on it, at 9.53:1.
| Hue family | Reds |
| Lightness | dark (40%) |
| Chroma | muted (0.060) |
| Temperature | warm |
| Nearest name | Purple Brown (#673A3F) |
| Black text | 2.20:1 |
| White text | 9.53:1 |
Values
| HEX | #643A37 |
| RGB | rgb(100, 58, 55) |
| HSL | hsl(4, 29%, 30%) |
| OKLCH | oklch(39.9% 0.06 24.5) |
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 #643A37 | 9.53:1 | AAA | Lc -96.2 | Preferred for body text |
| Black text on #643A37 | 2.20:1 | Fails | Lc 12.1 | Not readable |
| #643A37 text on white | 9.53:1 | AAA | Lc 91.9 | Preferred for body text |
| #643A37 text on black | 2.20:1 | Fails | Lc -10.5 | Not readable |
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 900.
-
Step 50
50
#F9F4F3
oklch(97.1% 0.006 31.1)
-
Step 100
100
#F3E7E5
oklch(93.7% 0.013 28.9)
-
Step 200
200
#E9D3D1
oklch(88.4% 0.025 23.9)
-
Step 300
300
#DDB6B2
oklch(80.9% 0.046 25)
-
Step 400
400
#CA8F8A
oklch(70.6% 0.073 24.5)
-
Step 500
500
#BB736D
oklch(63.1% 0.092 25.1)
-
Step 600
600
#A65A56
oklch(55.6% 0.1 24)
-
Step 700
700
#8E4A46
oklch(49.1% 0.093 24.5)
-
Step 800
800
#743D39
oklch(42.8% 0.078 25.2)
-
Step 900
900 (this color)
#643A37
oklch(39.9% 0.06 24.5)
-
Step 950
950
#371F1D
oklch(27% 0.038 25)
#643A37 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) | #434037 | 0.062 |
| Deuteranopia (no green cones) | #4D4936 | 0.059 |
| Tritanopia (no blue cones) | #6C3539 | 0.020 |
| Achromatopsia (no color) | #454545 | 0.061 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643A37
#643A37
oklch(39.9% 0.06 24.5)
- #145156
#145156
oklch(40% 0.06 203.1)
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 #643A37, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Purple Brown #673A3F ΔE 0.014
- Brownish Purple #76424E ΔE 0.053
- Chestnut #742802 ΔE 0.062
- Mud Brown #60460F ΔE 0.068
- Charcoal Grey #3C4142 ΔE 0.073
- Red Brown #8B2E16 ΔE 0.082
- Reddy Brown #6E1005 ΔE 0.086
- Rust Brown #8B3103 ΔE 0.086
Use #643A37 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.