#643F71
Closest named color: Dusk (#4E5481). oklch(43.1% 0.091 316.9), rgb(100, 63, 113).
Aa
White text reads best on this color (8.42:1).
About this color
#643F71 is a dark, moderately saturated purple. In OKLCH its lightness is 43%, its chroma 0.091 and its hue 317°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Dusk (#4E5481), ΔE 0.065 away. White text reads best on it, at 8.42:1.
| Hue family | Purples |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.091) |
| Temperature | in between |
| Nearest name | Dusk (#4E5481) |
| Black text | 2.49:1 |
| White text | 8.42:1 |
Values
| HEX | #643F71 |
| RGB | rgb(100, 63, 113) |
| HSL | hsl(284, 28%, 35%) |
| OKLCH | oklch(43.1% 0.091 316.9) |
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 #643F71 | 8.42:1 | AAA | Lc -93.5 | Preferred for body text |
| Black text on #643F71 | 2.49:1 | Fails | Lc 15.1 | Dividers and decoration only |
| #643F71 text on white | 8.42:1 | AAA | Lc 88.9 | Fine for body text |
| #643F71 text on black | 2.49:1 | Fails | Lc -13.3 | 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 800.
-
Step 50
50
#F7F4F9
oklch(97.1% 0.007 312.3)
-
Step 100
100
#EEE7F1
oklch(93.6% 0.015 316)
-
Step 200
200
#E1D3E6
oklch(88.4% 0.03 317.2)
-
Step 300
300
#CFB7D8
oklch(81% 0.053 316.8)
-
Step 400
400
#B690C4
oklch(70.6% 0.085 316.8)
-
Step 500
500
#A474B5
oklch(63.1% 0.109 317)
-
Step 600
600
#8F5CA1
oklch(55.7% 0.118 316.9)
-
Step 700
700
#794B8A
oklch(49.1% 0.11 316.4)
-
Step 800
800 (this color)
#643F71
oklch(43.1% 0.091 316.9)
-
Step 900
900
#51355A
oklch(37.7% 0.071 317.7)
-
Step 950
950
#2F1F35
oklch(26.9% 0.045 316.5)
#643F71 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) | #374B73 | 0.077 |
| Deuteranopia (no green cones) | #404E70 | 0.070 |
| Tritanopia (no blue cones) | #644652 | 0.061 |
| Achromatopsia (no color) | #4D4D4D | 0.092 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643F71
#643F71
oklch(43.1% 0.091 316.9)
- #375B26
#375B26
oklch(43% 0.091 136.7)
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 #643F71, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk #4E5481 ΔE 0.065
- Twilight #4E518B ΔE 0.065
- Dark Slate Blue #483D8B ΔE 0.068
- Dusty Grape #545775 ΔE 0.069
- Brownish Purple #76424E ΔE 0.071
- Rebecca Purple #663399 ΔE 0.075
- Light Eggplant #894585 ΔE 0.079
- Blueberry #464196 ΔE 0.080
Use #643F71 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.