#663D90
Closest named color: Rebecca Purple (#663399). oklch(44.9% 0.134 304.3), rgb(102, 61, 144).
Aa
White text reads best on this color (7.96:1).
About this color
#663D90 is a dark, moderately saturated purple. In OKLCH its lightness is 45%, its chroma 0.134 and its hue 304°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.027 away. White text reads best on it, at 7.96:1.
| Hue family | Purples |
| Lightness | dark (45%) |
| Chroma | moderately saturated (0.134) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.63:1 |
| White text | 7.96:1 |
Values
| HEX | #663D90 |
| RGB | rgb(102, 61, 144) |
| HSL | hsl(270, 40%, 40%) |
| OKLCH | oklch(44.9% 0.134 304.3) |
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 #663D90 | 7.96:1 | AAA | Lc -92.0 | Preferred for body text |
| Black text on #663D90 | 2.63:1 | Fails | Lc 16.7 | Dividers and decoration only |
| #663D90 text on white | 7.96:1 | AAA | Lc 87.3 | Fine for body text |
| #663D90 text on black | 2.63:1 | Fails | Lc -14.8 | 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
#F7F4FB
oklch(97.1% 0.01 305.4)
-
Step 100
100
#EDE6F7
oklch(93.5% 0.024 304.5)
-
Step 200
200
#DFD3F1
oklch(88.6% 0.043 303.7)
-
Step 300
300
#CCB4EA
oklch(80.8% 0.079 304.9)
-
Step 400
400
#B28CE0
oklch(70.7% 0.126 304.2)
-
Step 500
500
#9F6DD7
oklch(63.1% 0.16 304)
-
Step 600
600
#8B52C4
oklch(55.7% 0.174 304.4)
-
Step 700
700
#7641A9
oklch(49% 0.163 304.6)
-
Step 800
800 (this color)
#663D90
oklch(44.9% 0.134 304.3)
-
Step 900
900
#4E306E
oklch(37.6% 0.106 304.1)
-
Step 950
950
#2E1D40
oklch(27% 0.066 304.8)
#663D90 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) | #1D5093 | 0.105 |
| Deuteranopia (no green cones) | #2C518E | 0.095 |
| Tritanopia (no blue cones) | #5F4D60 | 0.100 |
| Achromatopsia (no color) | #515151 | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663D90
#663D90
oklch(44.9% 0.134 304.3)
- #485F00
#485F00
oklch(45% 0.112 124.4)
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 #663D90, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.027
- Dark Slate Blue #483D8B ΔE 0.055
- Blueberry #464196 ΔE 0.057
- Twilight #4E518B ΔE 0.064
- Light Eggplant #894585 ΔE 0.076
- Dusk #4E5481 ΔE 0.077
- Bluey Purple #6241C7 ΔE 0.088
- Warm Purple #952E8F ΔE 0.092
Use #663D90 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.