#643F7B
Closest named color: Dark Slate Blue (#483D8B). oklch(43.7% 0.104 311.2), rgb(100, 63, 123).
Aa
White text reads best on this color (8.27:1).
About this color
#643F7B is a dark, moderately saturated purple. In OKLCH its lightness is 44%, its chroma 0.104 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 8.27:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.104) |
| Temperature | in between |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.53:1 |
| White text | 8.27:1 |
Values
| HEX | #643F7B |
| RGB | rgb(100, 63, 123) |
| HSL | hsl(277, 32%, 36%) |
| OKLCH | oklch(43.7% 0.104 311.2) |
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 #643F7B | 8.27:1 | AAA | Lc -93.0 | Preferred for body text |
| Black text on #643F7B | 2.53:1 | Fails | Lc 15.6 | Dividers and decoration only |
| #643F7B text on white | 8.27:1 | AAA | Lc 88.4 | Fine for body text |
| #643F7B text on black | 2.53:1 | Fails | Lc -13.8 | 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
#B48FCD
oklch(70.6% 0.097 311.2)
-
Step 500
500
#A272C0
oklch(63.1% 0.124 311.5)
-
Step 600
600
#8D59AC
oklch(55.6% 0.135 311.6)
-
Step 700
700
#774994
oklch(49.1% 0.125 310.9)
-
Step 800
800 (this color)
#643F7B
oklch(43.7% 0.104 311.2)
-
Step 900
900
#4F3461
oklch(37.7% 0.081 310.7)
-
Step 950
950
#2E1F39
oklch(27% 0.051 309.8)
#643F7B 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) | #314D7D | 0.084 |
| Deuteranopia (no green cones) | #3B4F79 | 0.076 |
| Tritanopia (no blue cones) | #614857 | 0.072 |
| Achromatopsia (no color) | #4E4E4E | 0.104 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643F7B
#643F7B
oklch(43.7% 0.104 311.2)
- #3C5D17
#3C5D17
oklch(43.7% 0.104 131.5)
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 #643F7B, 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
- Twilight #4E518B ΔE 0.059
- Rebecca Purple #663399 ΔE 0.060
- Dusk #4E5481 ΔE 0.064
- Blueberry #464196 ΔE 0.068
- Dusty Grape #545775 ΔE 0.073
- Light Eggplant #894585 ΔE 0.075
- Brownish Purple #76424E ΔE 0.086
Use #643F7B 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.