#643537
Closest named color: Purple Brown (#673A3F). oklch(38.9% 0.067 18), rgb(100, 53, 55).
Aa
White text reads best on this color (9.97:1).
About this color
#643537 is a dark, muted red. In OKLCH its lightness is 39%, its chroma 0.067 and its hue 18°. Its hue sits on the warm side of the wheel. The nearest named color is Purple Brown (#673A3F), ΔE 0.017 away. White text reads best on it, at 9.97:1.
| Hue family | Reds |
| Lightness | dark (39%) |
| Chroma | muted (0.067) |
| Temperature | warm |
| Nearest name | Purple Brown (#673A3F) |
| Black text | 2.10:1 |
| White text | 9.97:1 |
Values
| HEX | #643537 |
| RGB | rgb(100, 53, 55) |
| HSL | hsl(357, 31%, 30%) |
| OKLCH | oklch(38.9% 0.067 18) |
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 #643537 | 9.97:1 | AAA | Lc -97.1 | Preferred for body text |
| Black text on #643537 | 2.10:1 | Fails | Lc 11.0 | Not readable |
| #643537 text on white | 9.97:1 | AAA | Lc 92.9 | Preferred for body text |
| #643537 text on black | 2.10:1 | Fails | Lc -9.6 | 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
#FAF4F4
oklch(97.2% 0.006 17.3)
-
Step 100
100
#F4E6E6
oklch(93.6% 0.015 17.4)
-
Step 200
200
#EBD2D2
oklch(88.4% 0.028 17.7)
-
Step 300
300
#E0B4B4
oklch(80.9% 0.051 18.3)
-
Step 400
400
#CE8C8E
oklch(70.7% 0.081 17.3)
-
Step 500
500
#C06F72
oklch(63.2% 0.103 18)
-
Step 600
600
#AB555A
oklch(55.5% 0.113 17.8)
-
Step 700
700
#93454A
oklch(49.1% 0.105 17.8)
-
Step 800
800
#77393D
oklch(42.6% 0.087 17.4)
-
Step 900
900 (this color)
#643537
oklch(38.9% 0.067 18)
-
Step 950
950
#391D1E
oklch(26.9% 0.044 18.1)
#643537 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) | #3F3D37 | 0.071 |
| Deuteranopia (no green cones) | #4A4636 | 0.067 |
| Tritanopia (no blue cones) | #6C2F36 | 0.020 |
| Achromatopsia (no color) | #434343 | 0.068 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643537
#643537
oklch(38.9% 0.067 18)
- #004F51
#004F51
oklch(38.8% 0.066 197.7)
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 #643537, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Purple Brown #673A3F ΔE 0.017
- Brownish Purple #76424E ΔE 0.059
- Chestnut #742802 ΔE 0.060
- Charcoal Grey #3C4142 ΔE 0.076
- Reddy Brown #6E1005 ΔE 0.077
- Mud Brown #60460F ΔE 0.080
- Wine Red #7B0323 ΔE 0.081
- Bordeaux #7B002C ΔE 0.084
Use #643537 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.