#643E78
Closest named color: Dark Slate Blue (#483D8B). oklch(43.3% 0.102 313), rgb(100, 62, 120).
Aa
White text reads best on this color (8.39:1).
About this color
#643E78 is a dark, moderately saturated purple. In OKLCH its lightness is 43%, its chroma 0.102 and its hue 313°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.061 away. White text reads best on it, at 8.39:1.
| Hue family | Purples |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.102) |
| Temperature | in between |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.50:1 |
| White text | 8.39:1 |
Values
| HEX | #643E78 |
| RGB | rgb(100, 62, 120) |
| HSL | hsl(279, 32%, 36%) |
| OKLCH | oklch(43.3% 0.102 313) |
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 #643E78 | 8.39:1 | AAA | Lc -93.3 | Preferred for body text |
| Black text on #643E78 | 2.50:1 | Fails | Lc 15.3 | Dividers and decoration only |
| #643E78 text on white | 8.39:1 | AAA | Lc 88.7 | Fine for body text |
| #643E78 text on black | 2.50:1 | Fails | Lc -13.5 | 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 800.
-
Step 50
50
#F7F4F9
oklch(97.1% 0.007 312.3)
-
Step 100
100
#EEE7F2
oklch(93.7% 0.016 313.6)
-
Step 200
200
#E1D3E9
oklch(88.5% 0.033 313.5)
-
Step 300
300
#CEB6DC
oklch(80.9% 0.059 313.1)
-
Step 400
400
#B58FCB
oklch(70.6% 0.095 312.8)
-
Step 500
500
#A372BD
oklch(63% 0.121 313.2)
-
Step 600
600
#8E59AA
oklch(55.6% 0.133 312.9)
-
Step 700
700
#794992
oklch(49.2% 0.123 313)
-
Step 800
800 (this color)
#643E78
oklch(43.3% 0.102 313)
-
Step 900
900
#50345F
oklch(37.7% 0.079 313)
-
Step 950
950
#2F1F38
oklch(27.1% 0.05 312.7)
#643E78 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) | #324B7A | 0.083 |
| Deuteranopia (no green cones) | #3C4E76 | 0.076 |
| Tritanopia (no blue cones) | #624755 | 0.070 |
| Achromatopsia (no color) | #4D4D4D | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643E78
#643E78
oklch(43.3% 0.102 313)
- #395C1B
#395C1B
oklch(43.3% 0.101 133.3)
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 #643E78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.061
- Twilight #4E518B ΔE 0.062
- Rebecca Purple #663399 ΔE 0.063
- Dusk #4E5481 ΔE 0.066
- Blueberry #464196 ΔE 0.072
- Dusty Grape #545775 ΔE 0.074
- Light Eggplant #894585 ΔE 0.077
- Brownish Purple #76424E ΔE 0.082
Use #643E78 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.