#663E99
Closest named color: Rebecca Purple (#663399). oklch(45.7% 0.144 301.1), rgb(102, 62, 153).
Aa
White text reads best on this color (7.73:1).
About this color
#663E99 is a medium-dark, vivid purple. In OKLCH its lightness is 46%, its chroma 0.144 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 7.73:1.
| Hue family | Purples |
| Lightness | medium-dark (46%) |
| Chroma | vivid (0.144) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.71:1 |
| White text | 7.73:1 |
Values
| HEX | #663E99 |
| RGB | rgb(102, 62, 153) |
| HSL | hsl(266, 42%, 42%) |
| OKLCH | oklch(45.7% 0.144 301.1) |
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 #663E99 | 7.73:1 | AAA | Lc -91.3 | Preferred for body text |
| Black text on #663E99 | 2.71:1 | Fails | Lc 17.5 | Dividers and decoration only |
| #663E99 text on white | 7.73:1 | AAA | Lc 86.5 | Fine for body text |
| #663E99 text on black | 2.71:1 | Fails | Lc -15.6 | 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 800.
-
Step 50
50
#F7F4FC
oklch(97.2% 0.011 303.1)
-
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
#CAB4EF
oklch(80.9% 0.085 301.6)
-
Step 400
400
#AF8BE7
oklch(70.6% 0.135 301)
-
Step 500
500
#9C6BDF
oklch(63% 0.172 301.1)
-
Step 600
600
#8850CD
oklch(55.6% 0.187 301.2)
-
Step 700
700
#733FB1
oklch(49% 0.174 301.2)
-
Step 800
800 (this color)
#663E99
oklch(45.7% 0.144 301.1)
-
Step 900
900
#4D3073
oklch(37.9% 0.112 301.2)
-
Step 950
950
#2D1D43
oklch(27.1% 0.07 301.3)
#663E99 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) | #11529C | 0.110 |
| Deuteranopia (no green cones) | #245297 | 0.100 |
| Tritanopia (no blue cones) | #5C5165 | 0.110 |
| Achromatopsia (no color) | #535353 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663E99
#663E99
oklch(45.7% 0.144 301.1)
- #4E6000
#4E6000
oklch(45.7% 0.11 121.5)
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 #663E99, 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 0.058
- Twilight #4E518B ΔE 0.066
- Bluey Purple #6241C7 ΔE 0.074
- Light Eggplant #894585 ΔE 0.080
- Blue With A Hint Of Purple #533CC6 ΔE 0.081
- Dusk #4E5481 ΔE 0.082
Use #663E99 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.