#663FA6
Closest named color: Rebecca Purple (#663399). oklch(46.7% 0.159 297.3), rgb(102, 63, 166).
Aa
White text reads best on this color (7.42:1).
About this color
#663FA6 is a medium-dark, vivid purple. In OKLCH its lightness is 47%, its chroma 0.159 and its hue 297°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.032 away. White text reads best on it, at 7.42:1.
| Hue family | Purples |
| Lightness | medium-dark (47%) |
| Chroma | vivid (0.159) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.82:1 |
| White text | 7.42:1 |
Values
| HEX | #663FA6 |
| RGB | rgb(102, 63, 166) |
| HSL | hsl(263, 45%, 45%) |
| OKLCH | oklch(46.7% 0.159 297.3) |
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 #663FA6 | 7.42:1 | AAA | Lc -90.3 | Preferred for body text |
| Black text on #663FA6 | 2.82:1 | Fails | Lc 18.6 | Dividers and decoration only |
| #663FA6 text on white | 7.42:1 | AAA | Lc 85.4 | Fine for body text |
| #663FA6 text on black | 2.82:1 | Fails | Lc -16.6 | 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 700.
-
Step 50
50
#F6F4FC
oklch(97.1% 0.011 297.6)
-
Step 100
100
#EBE7F7
oklch(93.6% 0.022 297.4)
-
Step 200
200
#DCD4F3
oklch(88.6% 0.043 297.3)
-
Step 300
300
#C6B7ED
oklch(81% 0.077 297.4)
-
Step 400
400
#A98FE4
oklch(70.7% 0.124 297.2)
-
Step 500
500
#9571DB
oklch(63% 0.157 297.4)
-
Step 600
600
#8057C9
oklch(55.6% 0.171 297.1)
-
Step 700
700 (this color)
#663FA6
oklch(46.7% 0.159 297.3)
-
Step 800
800
#583A8D
oklch(42.6% 0.133 297.1)
-
Step 900
900
#483370
oklch(37.6% 0.102 297.1)
-
Step 950
950
#2A1E42
oklch(26.9% 0.066 297.1)
#663FA6 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) | #0056A9 | 0.113 |
| Deuteranopia (no green cones) | #0F54A4 | 0.109 |
| Tritanopia (no blue cones) | #57566C | 0.124 |
| Achromatopsia (no color) | #555555 | 0.160 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663FA6
#663FA6
oklch(46.7% 0.159 297.3)
- #566100
#566100
oklch(46.7% 0.108 117.2)
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 #663FA6, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.032
- Bluey Purple #6241C7 ΔE 0.053
- Blueberry #464196 ΔE 0.061
- Blue With A Hint Of Purple #533CC6 ΔE 0.063
- Dark Slate Blue #483D8B ΔE 0.069
- Blurple #5539CC ΔE 0.070
- Iris #6258C4 ΔE 0.071
- Twilight #4E518B ΔE 0.075
Use #663FA6 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.