#663B88
Closest named color: Rebecca Purple (#663399). oklch(44% 0.128 307.8), rgb(102, 59, 136).
Aa
White text reads best on this color (8.24:1).
About this color
#663B88 is a dark, moderately saturated purple. In OKLCH its lightness is 44%, its chroma 0.128 and its hue 308°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.034 away. White text reads best on it, at 8.24:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.128) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.54:1 |
| White text | 8.24:1 |
Values
| HEX | #663B88 |
| RGB | rgb(102, 59, 136) |
| HSL | hsl(274, 39%, 38%) |
| OKLCH | oklch(44% 0.128 307.8) |
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 #663B88 | 8.24:1 | AAA | Lc -92.8 | Preferred for body text |
| Black text on #663B88 | 2.54:1 | Fails | Lc 15.8 | Dividers and decoration only |
| #663B88 text on white | 8.24:1 | AAA | Lc 88.2 | Fine for body text |
| #663B88 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
#F7F4FB
oklch(97.1% 0.01 305.4)
-
Step 100
100
#EEE6F5
oklch(93.6% 0.022 309.6)
-
Step 200
200
#E1D2EF
oklch(88.5% 0.042 308.6)
-
Step 300
300
#CEB4E6
oklch(80.9% 0.075 308.3)
-
Step 400
400
#B58CDA
oklch(70.8% 0.119 307.7)
-
Step 500
500
#A36DD0
oklch(63.2% 0.153 307.8)
-
Step 600
600
#8E52BD
oklch(55.6% 0.167 307.7)
-
Step 700
700
#7942A3
oklch(49.1% 0.155 307.8)
-
Step 800
800 (this color)
#663B88
oklch(44% 0.128 307.8)
-
Step 900
900
#50316A
oklch(37.8% 0.099 307.4)
-
Step 950
950
#2F1D3E
oklch(27% 0.063 307.9)
#663B88 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) | #224D8B | 0.104 |
| Deuteranopia (no green cones) | #314F86 | 0.093 |
| Tritanopia (no blue cones) | #61495B | 0.092 |
| Achromatopsia (no color) | #4F4F4F | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663B88
#663B88
oklch(44% 0.128 307.8)
- #405E00
#405E00
oklch(44.2% 0.115 128)
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 #663B88, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.034
- Dark Slate Blue #483D8B ΔE 0.054
- Blueberry #464196 ΔE 0.061
- Twilight #4E518B ΔE 0.066
- Light Eggplant #894585 ΔE 0.075
- Dusk #4E5481 ΔE 0.077
- Purple #800080 ΔE 0.089
- Dusty Grape #545775 ΔE 0.091
Use #663B88 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.