#643F89
Closest named color: Rebecca Purple (#663399). oklch(44.5% 0.122 305.1), rgb(100, 63, 137).
Aa
White text reads best on this color (8.03:1).
About this color
#643F89 is a dark, moderately saturated purple. In OKLCH its lightness is 45%, its chroma 0.122 and its hue 305°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.039 away. White text reads best on it, at 8.03:1.
| Hue family | Purples |
| Lightness | dark (45%) |
| Chroma | moderately saturated (0.122) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.61:1 |
| White text | 8.03:1 |
Values
| HEX | #643F89 |
| RGB | rgb(100, 63, 137) |
| HSL | hsl(270, 37%, 39%) |
| OKLCH | oklch(44.5% 0.122 305.1) |
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 #643F89 | 8.03:1 | AAA | Lc -92.3 | Preferred for body text |
| Black text on #643F89 | 2.61:1 | Fails | Lc 16.4 | Dividers and decoration only |
| #643F89 text on white | 8.03:1 | AAA | Lc 87.6 | Fine for body text |
| #643F89 text on black | 2.61:1 | Fails | Lc -14.6 | 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
#EDE7F5
oklch(93.7% 0.02 305.3)
-
Step 200
200
#DFD3EF
oklch(88.5% 0.04 304.9)
-
Step 300
300
#CBB6E6
oklch(81% 0.07 304.8)
-
Step 400
400
#B18ED9
oklch(70.7% 0.113 305.1)
-
Step 500
500
#9E70CF
oklch(63.1% 0.145 305)
-
Step 600
600
#8956BC
oklch(55.6% 0.158 304.9)
-
Step 700
700
#7546A2
oklch(49.2% 0.146 305.2)
-
Step 800
800 (this color)
#643F89
oklch(44.5% 0.122 305.1)
-
Step 900
900
#4D3269
oklch(37.5% 0.095 304.9)
-
Step 950
950
#2D1E3E
oklch(27% 0.06 304.3)
#643F89 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) | #274F8C | 0.093 |
| Deuteranopia (no green cones) | #335087 | 0.084 |
| Tritanopia (no blue cones) | #5E4C5E | 0.088 |
| Achromatopsia (no color) | #505050 | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643F89
#643F89
oklch(44.5% 0.122 305.1)
- #465E00
#465E00
oklch(44.6% 0.112 125)
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 #643F89, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.039
- Dark Slate Blue #483D8B ΔE 0.051
- Blueberry #464196 ΔE 0.056
- Twilight #4E518B ΔE 0.056
- Dusk #4E5481 ΔE 0.068
- Light Eggplant #894585 ΔE 0.075
- Dusty Grape #545775 ΔE 0.083
- Denim Blue #3B5B92 ΔE 0.090
Use #643F89 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.