#663F70
Closest named color: Dusk (#4E5481). oklch(43.3% 0.091 319.2), rgb(102, 63, 112).
Aa
White text reads best on this color (8.36:1).
About this color
#663F70 is a dark, moderately saturated purple. In OKLCH its lightness is 43%, its chroma 0.091 and its hue 319°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Dusk (#4E5481), ΔE 0.067 away. White text reads best on it, at 8.36:1.
| Hue family | Purples |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.091) |
| Temperature | in between |
| Nearest name | Dusk (#4E5481) |
| Black text | 2.50:1 |
| White text | 8.36:1 |
Values
| HEX | #663F70 |
| RGB | rgb(102, 63, 112) |
| HSL | hsl(288, 28%, 34%) |
| OKLCH | oklch(43.3% 0.091 319.2) |
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 #663F70 | 8.36:1 | AAA | Lc -93.3 | Preferred for body text |
| Black text on #663F70 | 2.50:1 | Fails | Lc 15.3 | Dividers and decoration only |
| #663F70 text on white | 8.36:1 | AAA | Lc 88.7 | Fine for body text |
| #663F70 text on black | 2.50:1 | Fails | Lc -13.5 | 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
#F8F4F8
oklch(97.1% 0.007 325.6)
-
Step 100
100
#EEE7F0
oklch(93.6% 0.014 318.7)
-
Step 200
200
#E2D3E6
oklch(88.5% 0.03 319.1)
-
Step 300
300
#D0B6D7
oklch(80.9% 0.054 319)
-
Step 400
400
#B890C2
oklch(70.8% 0.084 319.5)
-
Step 500
500
#A673B3
oklch(63.1% 0.109 319.3)
-
Step 600
600
#915B9F
oklch(55.7% 0.118 319.2)
-
Step 700
700
#7B4A88
oklch(49.1% 0.111 319)
-
Step 800
800 (this color)
#663F70
oklch(43.3% 0.091 319.2)
-
Step 900
900
#523559
oklch(37.8% 0.07 319.7)
-
Step 950
950
#301F34
oklch(27% 0.045 319.8)
#663F70 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) | #384B72 | 0.079 |
| Deuteranopia (no green cones) | #424F6F | 0.072 |
| Tritanopia (no blue cones) | #664552 | 0.058 |
| Achromatopsia (no color) | #4E4E4E | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663F70
#663F70
oklch(43.3% 0.091 319.2)
- #345C29
#345C29
oklch(43.2% 0.091 139.2)
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 #663F70, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk #4E5481 ΔE 0.067
- Twilight #4E518B ΔE 0.068
- Brownish Purple #76424E ΔE 0.068
- Dusty Grape #545775 ΔE 0.070
- Dark Slate Blue #483D8B ΔE 0.072
- Light Eggplant #894585 ΔE 0.077
- Rebecca Purple #663399 ΔE 0.077
- Purple Brown #673A3F ΔE 0.079
Use #663F70 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.