#663F87
Closest named color: Rebecca Purple (#663399). oklch(44.6% 0.12 307.2), rgb(102, 63, 135).
Aa
White text reads best on this color (7.99:1).
About this color
#663F87 is a dark, moderately saturated purple. In OKLCH its lightness is 45%, its chroma 0.120 and its hue 307°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.042 away. White text reads best on it, at 7.99:1.
| Hue family | Purples |
| Lightness | dark (45%) |
| Chroma | moderately saturated (0.120) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.62:1 |
| White text | 7.99:1 |
Values
| HEX | #663F87 |
| RGB | rgb(102, 63, 135) |
| HSL | hsl(273, 36%, 39%) |
| OKLCH | oklch(44.6% 0.12 307.2) |
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 #663F87 | 7.99:1 | AAA | Lc -92.2 | Preferred for body text |
| Black text on #663F87 | 2.62:1 | Fails | Lc 16.5 | Dividers and decoration only |
| #663F87 text on white | 7.99:1 | AAA | Lc 87.5 | Fine for body text |
| #663F87 text on black | 2.62:1 | Fails | Lc -14.7 | 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
#F7F4FA
oklch(97.1% 0.009 308.4)
-
Step 100
100
#EDE7F5
oklch(93.7% 0.02 305.3)
-
Step 200
200
#E0D3EE
oklch(88.6% 0.039 307.2)
-
Step 300
300
#CDB5E4
oklch(80.9% 0.07 308)
-
Step 400
400
#B38DD7
oklch(70.6% 0.113 307.3)
-
Step 500
500
#A16FCC
oklch(63.1% 0.144 307.6)
-
Step 600
600
#8C56B9
oklch(55.7% 0.155 307.3)
-
Step 700
700
#77459F
oklch(49.1% 0.145 307.6)
-
Step 800
800 (this color)
#663F87
oklch(44.6% 0.12 307.2)
-
Step 900
900
#4F3268
oklch(37.7% 0.094 307.3)
-
Step 950
950
#2E1E3D
oklch(27% 0.059 306.7)
#663F87 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) | #2A4F89 | 0.094 |
| Deuteranopia (no green cones) | #365185 | 0.085 |
| Tritanopia (no blue cones) | #614C5D | 0.087 |
| Achromatopsia (no color) | #515151 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663F87
#663F87
oklch(44.6% 0.12 307.2)
- #425F00
#425F00
oklch(44.6% 0.116 127.4)
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 #663F87, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.042
- Dark Slate Blue #483D8B ΔE 0.055
- Twilight #4E518B ΔE 0.058
- Blueberry #464196 ΔE 0.061
- Dusk #4E5481 ΔE 0.068
- Light Eggplant #894585 ΔE 0.071
- Dusty Grape #545775 ΔE 0.082
- Muted Purple #805B87 ΔE 0.092
Use #663F87 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.