#643F7C
Closest named color: Dark Slate Blue (#483D8B). oklch(43.7% 0.105 310.7), rgb(100, 63, 124).
Aa
White text reads best on this color (8.25:1).
About this color
#643F7C is a dark, moderately saturated purple. In OKLCH its lightness is 44%, its chroma 0.105 and its hue 311°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.058 away. White text reads best on it, at 8.25:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.105) |
| Temperature | in between |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.54:1 |
| White text | 8.25:1 |
Values
| HEX | #643F7C |
| RGB | rgb(100, 63, 124) |
| HSL | hsl(276, 33%, 37%) |
| OKLCH | oklch(43.7% 0.105 310.7) |
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 #643F7C | 8.25:1 | AAA | Lc -92.9 | Preferred for body text |
| Black text on #643F7C | 2.54:1 | Fails | Lc 15.7 | Dividers and decoration only |
| #643F7C text on white | 8.25:1 | AAA | Lc 88.3 | Fine for body text |
| #643F7C text on black | 2.54:1 | Fails | Lc -13.9 | 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
#F7F4FA
oklch(97.1% 0.009 308.4)
-
Step 100
100
#EEE7F3
oklch(93.7% 0.018 311.6)
-
Step 200
200
#E0D3EA
oklch(88.4% 0.034 310.7)
-
Step 300
300
#CDB6DE
oklch(80.9% 0.061 310.8)
-
Step 400
400
#B48FCE
oklch(70.7% 0.098 310.8)
-
Step 500
500
#A172C1
oklch(63% 0.125 310.6)
-
Step 600
600
#8C59AD
oklch(55.5% 0.136 310.7)
-
Step 700
700
#774995
oklch(49.1% 0.126 310.5)
-
Step 800
800 (this color)
#643F7C
oklch(43.7% 0.105 310.7)
-
Step 900
900
#4F3461
oklch(37.7% 0.081 310.7)
-
Step 950
950
#2E1F39
oklch(27% 0.051 309.8)
#643F7C 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) | #314D7E | 0.084 |
| Deuteranopia (no green cones) | #3B4F7A | 0.076 |
| Tritanopia (no blue cones) | #614957 | 0.075 |
| Achromatopsia (no color) | #4F4F4F | 0.105 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643F7C
#643F7C
oklch(43.7% 0.105 310.7)
- #3D5D15
#3D5D15
oklch(43.8% 0.105 130.7)
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 #643F7C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.058
- Rebecca Purple #663399 ΔE 0.058
- Twilight #4E518B ΔE 0.058
- Dusk #4E5481 ΔE 0.064
- Blueberry #464196 ΔE 0.067
- Dusty Grape #545775 ΔE 0.074
- Light Eggplant #894585 ΔE 0.075
- Brownish Purple #76424E ΔE 0.087
Use #643F7C 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.