#66378F
Closest named color: Rebecca Purple (#663399). oklch(43.9% 0.143 306), rgb(102, 55, 143).
Aa
White text reads best on this color (8.37:1).
About this color
#66378F is a dark, vivid purple. In OKLCH its lightness is 44%, its chroma 0.143 and its hue 306°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.019 away. White text reads best on it, at 8.37:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | vivid (0.143) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.50:1 |
| White text | 8.37:1 |
Values
| HEX | #66378F |
| RGB | rgb(102, 55, 143) |
| HSL | hsl(272, 44%, 39%) |
| OKLCH | oklch(43.9% 0.143 306) |
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 #66378F | 8.37:1 | AAA | Lc -93.1 | Preferred for body text |
| Black text on #66378F | 2.50:1 | Fails | Lc 15.5 | Dividers and decoration only |
| #66378F text on white | 8.37:1 | AAA | Lc 88.5 | Fine for body text |
| #66378F text on black | 2.50:1 | Fails | Lc -13.7 | 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
#F7F4FC
oklch(97.2% 0.011 303.1)
-
Step 100
100
#EEE6F7
oklch(93.6% 0.024 307)
-
Step 200
200
#E0D2F2
oklch(88.5% 0.046 305.2)
-
Step 300
300
#CEB3EC
oklch(80.9% 0.084 306.1)
-
Step 400
400
#B589E2
oklch(70.6% 0.134 306)
-
Step 500
500
#A369DA
oklch(63.1% 0.171 305.8)
-
Step 600
600
#8F4DC7
oklch(55.6% 0.186 306.2)
-
Step 700
700
#793DAC
oklch(49% 0.173 305.8)
-
Step 800
800 (this color)
#66378F
oklch(43.9% 0.143 306)
-
Step 900
900
#502E6F
oklch(37.6% 0.111 305.9)
-
Step 950
950
#2F1C41
oklch(27% 0.07 306)
#66378F 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) | #0D4C92 | 0.119 |
| Deuteranopia (no green cones) | #264E8D | 0.106 |
| Tritanopia (no blue cones) | #5F485D | 0.103 |
| Achromatopsia (no color) | #4E4E4E | 0.143 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66378F
#66378F
oklch(43.9% 0.143 306)
- #435C00
#435C00
oklch(43.8% 0.111 125.8)
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 #66378F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.019
- Dark Slate Blue #483D8B ΔE 0.055
- Blueberry #464196 ΔE 0.060
- Twilight #4E518B ΔE 0.075
- Light Eggplant #894585 ΔE 0.083
- Purple #800080 ΔE 0.084
- Grape #7209B7 ΔE 0.086
- Dusk #4E5481 ΔE 0.088
Use #66378F 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.