#643B90
Closest named color: Rebecca Purple (#663399). oklch(44.3% 0.137 303.5), rgb(100, 59, 144).
Aa
White text reads best on this color (8.17:1).
About this color
#643B90 is a dark, moderately saturated purple. In OKLCH its lightness is 44%, its chroma 0.137 and its hue 304°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.023 away. White text reads best on it, at 8.17:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.137) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.57:1 |
| White text | 8.17:1 |
Values
| HEX | #643B90 |
| RGB | rgb(100, 59, 144) |
| HSL | hsl(269, 42%, 40%) |
| OKLCH | oklch(44.3% 0.137 303.5) |
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 #643B90 | 8.17:1 | AAA | Lc -92.6 | Preferred for body text |
| Black text on #643B90 | 2.57:1 | Fails | Lc 16.1 | Dividers and decoration only |
| #643B90 text on white | 8.17:1 | AAA | Lc 87.9 | Fine for body text |
| #643B90 text on black | 2.57:1 | Fails | Lc -14.2 | 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
#F7F4FC
oklch(97.2% 0.011 303.1)
-
Step 100
100
#EDE6F7
oklch(93.5% 0.024 304.5)
-
Step 200
200
#DFD3F2
oklch(88.6% 0.044 303.1)
-
Step 300
300
#CBB4EC
oklch(80.8% 0.081 303.4)
-
Step 400
400
#B18CE2
oklch(70.8% 0.128 303.1)
-
Step 500
500
#9F6CD9
oklch(63.1% 0.164 303.7)
-
Step 600
600
#8A51C6
oklch(55.5% 0.178 303.6)
-
Step 700
700
#7541AB
oklch(49% 0.165 303.5)
-
Step 800
800 (this color)
#643B90
oklch(44.3% 0.137 303.5)
-
Step 900
900
#4E306F
oklch(37.7% 0.107 303.7)
-
Step 950
950
#2E1D41
oklch(27.1% 0.067 304.1)
#643B90 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) | #174E93 | 0.107 |
| Deuteranopia (no green cones) | #284F8E | 0.097 |
| Tritanopia (no blue cones) | #5C4C5F | 0.103 |
| Achromatopsia (no color) | #4F4F4F | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643B90
#643B90
oklch(44.3% 0.137 303.5)
- #485D00
#485D00
oklch(44.5% 0.11 123.5)
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 #643B90, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.023
- Dark Slate Blue #483D8B ΔE 0.051
- Blueberry #464196 ΔE 0.054
- Twilight #4E518B ΔE 0.066
- Dusk #4E5481 ΔE 0.080
- Light Eggplant #894585 ΔE 0.082
- Bluey Purple #6241C7 ΔE 0.089
- Grape #7209B7 ΔE 0.091
Use #643B90 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.