#643B78
Closest named color: Rebecca Purple (#663399). oklch(42.8% 0.107 313.7), rgb(100, 59, 120).
Aa
White text reads best on this color (8.61:1).
About this color
#643B78 is a dark, moderately saturated purple. In OKLCH its lightness is 43%, its chroma 0.107 and its hue 314°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.059 away. White text reads best on it, at 8.61:1.
| Hue family | Purples |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.107) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.43:1 |
| White text | 8.61:1 |
Values
| HEX | #643B78 |
| RGB | rgb(100, 59, 120) |
| HSL | hsl(280, 34%, 35%) |
| OKLCH | oklch(42.8% 0.107 313.7) |
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 #643B78 | 8.61:1 | AAA | Lc -93.9 | Preferred for body text |
| Black text on #643B78 | 2.43:1 | Fails | Lc 14.7 | Not readable |
| #643B78 text on white | 8.61:1 | AAA | Lc 89.3 | Fine for body text |
| #643B78 text on black | 2.43:1 | Fails | Lc -12.9 | 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
#EEE7F3
oklch(93.7% 0.018 311.6)
-
Step 200
200
#E2D3EA
oklch(88.6% 0.035 314.1)
-
Step 300
300
#CFB5DE
oklch(80.8% 0.063 313.2)
-
Step 400
400
#B78ECD
oklch(70.7% 0.1 313.5)
-
Step 500
500
#A570C0
oklch(63.1% 0.129 313.6)
-
Step 600
600
#9057AC
oklch(55.6% 0.14 313.6)
-
Step 700
700
#7B4793
oklch(49.2% 0.129 314.2)
-
Step 800
800 (this color)
#643B78
oklch(42.8% 0.107 313.7)
-
Step 900
900
#513360
oklch(37.7% 0.082 313.7)
-
Step 950
950
#301E38
oklch(27% 0.053 314.9)
#643B78 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) | #2E4A7A | 0.090 |
| Deuteranopia (no green cones) | #3A4D76 | 0.081 |
| Tritanopia (no blue cones) | #624454 | 0.072 |
| Achromatopsia (no color) | #4C4C4C | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #643B78
#643B78
oklch(42.8% 0.107 313.7)
- #365B15
#365B15
oklch(42.8% 0.106 133.5)
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 #643B78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.059
- Dark Slate Blue #483D8B ΔE 0.060
- Twilight #4E518B ΔE 0.068
- Blueberry #464196 ΔE 0.072
- Dusk #4E5481 ΔE 0.072
- Light Eggplant #894585 ΔE 0.080
- Dusty Grape #545775 ΔE 0.081
- Brownish Purple #76424E ΔE 0.086
Use #643B78 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.