#663F7D
Closest named color: Rebecca Purple (#663399). oklch(44% 0.107 311.7), rgb(102, 63, 125).
Aa
White text reads best on this color (8.16:1).
About this color
#663F7D is a dark, moderately saturated purple. In OKLCH its lightness is 44%, its chroma 0.107 and its hue 312°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.057 away. White text reads best on it, at 8.16:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.107) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.57:1 |
| White text | 8.16:1 |
Values
| HEX | #663F7D |
| RGB | rgb(102, 63, 125) |
| HSL | hsl(278, 33%, 37%) |
| OKLCH | oklch(44% 0.107 311.7) |
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 #663F7D | 8.16:1 | AAA | Lc -92.7 | Preferred for body text |
| Black text on #663F7D | 2.57:1 | Fails | Lc 16.0 | Dividers and decoration only |
| #663F7D text on white | 8.16:1 | AAA | Lc 88.0 | Fine for body text |
| #663F7D text on black | 2.57:1 | Fails | Lc -14.1 | 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
#EEE7F3
oklch(93.7% 0.018 311.6)
-
Step 200
200
#E1D3EA
oklch(88.5% 0.035 312.4)
-
Step 300
300
#CEB6DF
oklch(81% 0.062 311.2)
-
Step 400
400
#B58ECE
oklch(70.6% 0.1 311.7)
-
Step 500
500
#A371C1
oklch(63.1% 0.128 311.9)
-
Step 600
600
#8E58AE
oklch(55.6% 0.139 311.6)
-
Step 700
700
#794895
oklch(49.2% 0.129 311.9)
-
Step 800
800 (this color)
#663F7D
oklch(44% 0.107 311.7)
-
Step 900
900
#503361
oklch(37.6% 0.083 312)
-
Step 950
950
#2F1E39
oklch(26.9% 0.053 312.1)
#663F7D 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) | #314D7F | 0.087 |
| Deuteranopia (no green cones) | #3C507B | 0.079 |
| Tritanopia (no blue cones) | #644958 | 0.075 |
| Achromatopsia (no color) | #4F4F4F | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663F7D
#663F7D
oklch(44% 0.107 311.7)
- #3C5E16
#3C5E16
oklch(44% 0.106 131.6)
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 #663F7D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.057
- Twilight #4E518B ΔE 0.060
- Dark Slate Blue #483D8B ΔE 0.060
- Dusk #4E5481 ΔE 0.065
- Blueberry #464196 ΔE 0.069
- Light Eggplant #894585 ΔE 0.071
- Dusty Grape #545775 ΔE 0.075
- Brownish Purple #76424E ΔE 0.087
Use #663F7D 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.