#663F73
Closest named color: Twilight (#4E518B). oklch(43.5% 0.095 317.3), rgb(102, 63, 115).
Aa
White text reads best on this color (8.32:1).
About this color
#663F73 is a dark, moderately saturated purple. In OKLCH its lightness is 43%, its chroma 0.095 and its hue 317°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Twilight (#4E518B), ΔE 0.065 away. White text reads best on it, at 8.32:1.
| Hue family | Purples |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.095) |
| Temperature | in between |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.52:1 |
| White text | 8.32:1 |
Values
| HEX | #663F73 |
| RGB | rgb(102, 63, 115) |
| HSL | hsl(285, 29%, 35%) |
| OKLCH | oklch(43.5% 0.095 317.3) |
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 #663F73 | 8.32:1 | AAA | Lc -93.1 | Preferred for body text |
| Black text on #663F73 | 2.52:1 | Fails | Lc 15.5 | Dividers and decoration only |
| #663F73 text on white | 8.32:1 | AAA | Lc 88.5 | Fine for body text |
| #663F73 text on black | 2.52:1 | Fails | Lc -13.6 | 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
#F7F4F9
oklch(97.1% 0.007 312.3)
-
Step 100
100
#EEE7F1
oklch(93.6% 0.015 316)
-
Step 200
200
#E2D3E7
oklch(88.5% 0.031 317.7)
-
Step 300
300
#D0B6D9
oklch(80.9% 0.056 317.4)
-
Step 400
400
#B78FC5
oklch(70.6% 0.089 317.2)
-
Step 500
500
#A573B6
oklch(63.1% 0.112 317.3)
-
Step 600
600
#905AA2
oklch(55.5% 0.123 317.3)
-
Step 700
700
#7B4A8B
oklch(49.2% 0.114 317.4)
-
Step 800
800 (this color)
#663F73
oklch(43.5% 0.095 317.3)
-
Step 900
900
#51345B
oklch(37.6% 0.074 317.1)
-
Step 950
950
#301F35
oklch(27% 0.046 318.4)
#663F73 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) | #364B75 | 0.081 |
| Deuteranopia (no green cones) | #414F71 | 0.073 |
| Tritanopia (no blue cones) | #664653 | 0.062 |
| Achromatopsia (no color) | #4E4E4E | 0.095 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663F73
#663F73
oklch(43.5% 0.095 317.3)
- #365D26
#365D26
oklch(43.5% 0.095 137.5)
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 #663F73, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight #4E518B ΔE 0.065
- Dusk #4E5481 ΔE 0.066
- Dark Slate Blue #483D8B ΔE 0.069
- Dusty Grape #545775 ΔE 0.071
- Brownish Purple #76424E ΔE 0.072
- Rebecca Purple #663399 ΔE 0.072
- Light Eggplant #894585 ΔE 0.075
- Blueberry #464196 ΔE 0.080
Use #663F73 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.