#663F7B
Closest named color: Rebecca Purple (#663399). oklch(43.9% 0.104 312.8), rgb(102, 63, 123).
Aa
White text reads best on this color (8.19:1).
About this color
#663F7B is a dark, moderately saturated purple. In OKLCH its lightness is 44%, its chroma 0.104 and its hue 313°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.060 away. White text reads best on it, at 8.19:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.104) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.56:1 |
| White text | 8.19:1 |
Values
| HEX | #663F7B |
| RGB | rgb(102, 63, 123) |
| HSL | hsl(279, 32%, 36%) |
| OKLCH | oklch(43.9% 0.104 312.8) |
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 #663F7B | 8.19:1 | AAA | Lc -92.8 | Preferred for body text |
| Black text on #663F7B | 2.56:1 | Fails | Lc 15.9 | Dividers and decoration only |
| #663F7B text on white | 8.19:1 | AAA | Lc 88.1 | Fine for body text |
| #663F7B text on black | 2.56:1 | Fails | Lc -14.0 | 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
#EEE7F3
oklch(93.7% 0.018 311.6)
-
Step 200
200
#E1D3EA
oklch(88.5% 0.035 312.4)
-
Step 300
300
#CEB6DD
oklch(80.9% 0.06 312.4)
-
Step 400
400
#B68FCC
oklch(70.8% 0.097 313)
-
Step 500
500
#A372BF
oklch(63.1% 0.124 312.5)
-
Step 600
600
#8E58AB
oklch(55.5% 0.136 312.7)
-
Step 700
700
#794893
oklch(49.1% 0.126 312.8)
-
Step 800
800 (this color)
#663F7B
oklch(43.9% 0.104 312.8)
-
Step 900
900
#503360
oklch(37.5% 0.082 312.7)
-
Step 950
950
#2F1E38
oklch(26.9% 0.052 313.3)
#663F7B 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) | #324D7D | 0.086 |
| Deuteranopia (no green cones) | #3D5079 | 0.078 |
| Tritanopia (no blue cones) | #644857 | 0.072 |
| Achromatopsia (no color) | #4F4F4F | 0.105 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663F7B
#663F7B
oklch(43.9% 0.104 312.8)
- #3B5E1A
#3B5E1A
oklch(44% 0.104 132.7)
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 #663F7B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.060
- Twilight #4E518B ΔE 0.061
- Dark Slate Blue #483D8B ΔE 0.062
- Dusk #4E5481 ΔE 0.065
- Blueberry #464196 ΔE 0.071
- Light Eggplant #894585 ΔE 0.071
- Dusty Grape #545775 ΔE 0.074
- Brownish Purple #76424E ΔE 0.084
Use #663F7B 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.