#663D81
Closest named color: Rebecca Purple (#663399). oklch(43.9% 0.116 310.3), rgb(102, 61, 129).
Aa
White text reads best on this color (8.23:1).
About this color
#663D81 is a dark, moderately saturated purple. In OKLCH its lightness is 44%, its chroma 0.116 and its hue 310°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.048 away. White text reads best on it, at 8.23:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.116) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.54:1 |
| White text | 8.23:1 |
Values
| HEX | #663D81 |
| RGB | rgb(102, 61, 129) |
| HSL | hsl(276, 36%, 37%) |
| OKLCH | oklch(43.9% 0.116 310.3) |
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 #663D81 | 8.23:1 | AAA | Lc -92.8 | Preferred for body text |
| Black text on #663D81 | 2.54:1 | Fails | Lc 15.8 | Dividers and decoration only |
| #663D81 text on white | 8.23:1 | AAA | Lc 88.2 | Fine for body text |
| #663D81 text on black | 2.54:1 | Fails | Lc -14.0 | 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
#F7F4FA
oklch(97.1% 0.009 308.4)
-
Step 100
100
#EEE6F4
oklch(93.5% 0.021 311.1)
-
Step 200
200
#E1D3EC
oklch(88.6% 0.037 310.5)
-
Step 300
300
#CEB5E2
oklch(80.9% 0.068 309.9)
-
Step 400
400
#B68DD3
oklch(70.7% 0.109 310.6)
-
Step 500
500
#A36FC7
oklch(63% 0.138 310.2)
-
Step 600
600
#8E56B4
oklch(55.6% 0.15 309.9)
-
Step 700
700
#79459A
oklch(49% 0.14 310.5)
-
Step 800
800 (this color)
#663D81
oklch(43.9% 0.116 310.3)
-
Step 900
900
#503265
oklch(37.7% 0.091 309.8)
-
Step 950
950
#2F1E3B
oklch(27.1% 0.056 310.1)
#663D81 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) | #2B4D83 | 0.095 |
| Deuteranopia (no green cones) | #384F7F | 0.084 |
| Tritanopia (no blue cones) | #634859 | 0.080 |
| Achromatopsia (no color) | #4F4F4F | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663D81
#663D81
oklch(43.9% 0.116 310.3)
- #3C5E06
#3C5E06
oklch(43.9% 0.115 130.2)
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 #663D81, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.048
- Dark Slate Blue #483D8B ΔE 0.057
- Twilight #4E518B ΔE 0.062
- Blueberry #464196 ΔE 0.066
- Dusk #4E5481 ΔE 0.070
- Light Eggplant #894585 ΔE 0.072
- Dusty Grape #545775 ΔE 0.082
- Purple #800080 ΔE 0.093
Use #663D81 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.