#663B9A
Closest named color: Rebecca Purple (#663399). oklch(45.3% 0.15 301.5), rgb(102, 59, 154).
Aa
White text reads best on this color (7.90:1).
About this color
#663B9A is a medium-dark, vivid purple. In OKLCH its lightness is 45%, its chroma 0.150 and its hue 302°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.017 away. White text reads best on it, at 7.90:1.
| Hue family | Purples |
| Lightness | medium-dark (45%) |
| Chroma | vivid (0.150) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.65:1 |
| White text | 7.90:1 |
Values
| HEX | #663B9A |
| RGB | rgb(102, 59, 154) |
| HSL | hsl(267, 45%, 42%) |
| OKLCH | oklch(45.3% 0.15 301.5) |
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 #663B9A | 7.90:1 | AAA | Lc -91.7 | Preferred for body text |
| Black text on #663B9A | 2.65:1 | Fails | Lc 17.0 | Dividers and decoration only |
| #663B9A text on white | 7.90:1 | AAA | Lc 87.0 | Fine for body text |
| #663B9A text on black | 2.65:1 | Fails | Lc -15.1 | Dividers and decoration only |
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
#EDE6F9
oklch(93.6% 0.026 302.6)
-
Step 200
200
#DED2F5
oklch(88.4% 0.049 301)
-
Step 300
300
#CAB4F1
oklch(80.9% 0.088 301)
-
Step 400
400
#B08AE9
oklch(70.6% 0.14 301.3)
-
Step 500
500
#9E69E2
oklch(63% 0.179 301.7)
-
Step 600
600
#894DD0
oklch(55.5% 0.194 301.4)
-
Step 700
700
#753DB4
oklch(49.1% 0.181 301.7)
-
Step 800
800 (this color)
#663B9A
oklch(45.3% 0.15 301.5)
-
Step 900
900
#4D2E74
oklch(37.6% 0.117 301.4)
-
Step 950
950
#2D1C44
oklch(27% 0.073 301.3)
#663B9A 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) | #00519D | 0.118 |
| Deuteranopia (no green cones) | #1E5198 | 0.106 |
| Tritanopia (no blue cones) | #5B4F65 | 0.112 |
| Achromatopsia (no color) | #515151 | 0.151 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663B9A
#663B9A
oklch(45.3% 0.15 301.5)
- #4D5F00
#4D5F00
oklch(45.4% 0.11 121.6)
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 #663B9A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.017
- Blueberry #464196 ΔE 0.057
- Dark Slate Blue #483D8B ΔE 0.059
- Twilight #4E518B ΔE 0.072
- Bluey Purple #6241C7 ΔE 0.073
- Grape #7209B7 ΔE 0.079
- Blue With A Hint Of Purple #533CC6 ΔE 0.079
- Light Eggplant #894585 ΔE 0.084
Use #663B9A 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.