#643F8C
Closest named color: Rebecca Purple (#663399). oklch(44.7% 0.125 304), rgb(100, 63, 140).
Aa
White text reads best on this color (7.98:1).
About this color
#643F8C is a dark, moderately saturated purple. In OKLCH its lightness is 45%, its chroma 0.125 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 0.036 away. White text reads best on it, at 7.98:1.
| Hue family | Purples |
| Lightness | dark (45%) |
| Chroma | moderately saturated (0.125) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.63:1 |
| White text | 7.98:1 |
Values
| HEX | #643F8C |
| RGB | rgb(100, 63, 140) |
| HSL | hsl(269, 38%, 40%) |
| OKLCH | oklch(44.7% 0.125 304) |
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 #643F8C | 7.98:1 | AAA | Lc -92.1 | Preferred for body text |
| Black text on #643F8C | 2.63:1 | Fails | Lc 16.6 | Dividers and decoration only |
| #643F8C text on white | 7.98:1 | AAA | Lc 87.4 | Fine for body text |
| #643F8C text on black | 2.63:1 | Fails | Lc -14.7 | 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
#F7F4FB
oklch(97.1% 0.01 305.4)
-
Step 100
100
#EDE7F6
oklch(93.7% 0.021 304)
-
Step 200
200
#DFD3F0
oklch(88.5% 0.041 304.3)
-
Step 300
300
#CBB5E8
oklch(80.9% 0.074 304.4)
-
Step 400
400
#B08EDC
oklch(70.7% 0.117 303.6)
-
Step 500
500
#9D6FD2
oklch(63% 0.15 303.9)
-
Step 600
600
#8955BF
oklch(55.6% 0.163 304.3)
-
Step 700
700
#7445A5
oklch(49.1% 0.151 303.9)
-
Step 800
800 (this color)
#643F8C
oklch(44.7% 0.125 304)
-
Step 900
900
#4D326B
oklch(37.7% 0.098 304)
-
Step 950
950
#2D1E3F
oklch(27.1% 0.062 303.5)
#643F8C 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) | #24508F | 0.096 |
| Deuteranopia (no green cones) | #30518A | 0.087 |
| Tritanopia (no blue cones) | #5D4D5F | 0.093 |
| Achromatopsia (no color) | #515151 | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643F8C
#643F8C
oklch(44.7% 0.125 304)
- #485E00
#485E00
oklch(44.7% 0.111 123.9)
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 #643F8C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.036
- Dark Slate Blue #483D8B ΔE 0.051
- Blueberry #464196 ΔE 0.054
- Twilight #4E518B ΔE 0.057
- Dusk #4E5481 ΔE 0.070
- Light Eggplant #894585 ΔE 0.076
- Dusty Grape #545775 ΔE 0.086
- Denim Blue #3B5B92 ΔE 0.090
Use #643F8C 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.