#663E9B
Closest named color: Rebecca Purple (#663399). oklch(45.8% 0.147 300.5), rgb(102, 62, 155).
Aa
White text reads best on this color (7.69:1).
About this color
#663E9B is a medium-dark, vivid purple. In OKLCH its lightness is 46%, its chroma 0.147 and its hue 301°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.024 away. White text reads best on it, at 7.69:1.
| Hue family | Purples |
| Lightness | medium-dark (46%) |
| Chroma | vivid (0.147) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.72:1 |
| White text | 7.69:1 |
Values
| HEX | #663E9B |
| RGB | rgb(102, 62, 155) |
| HSL | hsl(266, 43%, 43%) |
| OKLCH | oklch(45.8% 0.147 300.5) |
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 #663E9B | 7.69:1 | AAA | Lc -91.2 | Preferred for body text |
| Black text on #663E9B | 2.72:1 | Fails | Lc 17.6 | Dividers and decoration only |
| #663E9B text on white | 7.69:1 | AAA | Lc 86.4 | Fine for body text |
| #663E9B text on black | 2.72:1 | Fails | Lc -15.7 | 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
#F6F4FC
oklch(97.1% 0.011 297.6)
-
Step 100
100
#ECE6F8
oklch(93.5% 0.025 301.1)
-
Step 200
200
#DED3F4
oklch(88.6% 0.046 300.7)
-
Step 300
300
#C9B4F0
oklch(80.8% 0.086 300.5)
-
Step 400
400
#AF8BE8
oklch(70.7% 0.137 300.8)
-
Step 500
500
#9C6BE1
oklch(63.1% 0.175 300.7)
-
Step 600
600
#874FCF
oklch(55.5% 0.19 300.4)
-
Step 700
700
#733FB3
oklch(49.1% 0.176 300.6)
-
Step 800
800 (this color)
#663E9B
oklch(45.8% 0.147 300.5)
-
Step 900
900
#4C2F74
oklch(37.6% 0.115 300.4)
-
Step 950
950
#2D1C44
oklch(27% 0.073 301.3)
#663E9B 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) | #0C539E | 0.111 |
| Deuteranopia (no green cones) | #215299 | 0.102 |
| Tritanopia (no blue cones) | #5B5166 | 0.111 |
| Achromatopsia (no color) | #535353 | 0.147 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663E9B
#663E9B
oklch(45.8% 0.147 300.5)
- #4F6000
#4F6000
oklch(45.8% 0.11 120.9)
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 #663E9B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.024
- Blueberry #464196 ΔE 0.056
- Dark Slate Blue #483D8B ΔE 0.059
- Twilight #4E518B ΔE 0.068
- Bluey Purple #6241C7 ΔE 0.071
- Blue With A Hint Of Purple #533CC6 ΔE 0.078
- Light Eggplant #894585 ΔE 0.082
- Grape #7209B7 ΔE 0.083
Use #663E9B 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.