#663B74
Closest named color: Rebecca Purple (#663399). oklch(42.8% 0.103 317.4), rgb(102, 59, 116).
Aa
White text reads best on this color (8.59:1).
About this color
#663B74 is a dark, moderately saturated purple. In OKLCH its lightness is 43%, its chroma 0.103 and its hue 317°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.066 away. White text reads best on it, at 8.59:1.
| Hue family | Purples |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.103) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.44:1 |
| White text | 8.59:1 |
Values
| HEX | #663B74 |
| RGB | rgb(102, 59, 116) |
| HSL | hsl(285, 33%, 34%) |
| OKLCH | oklch(42.8% 0.103 317.4) |
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 #663B74 | 8.59:1 | AAA | Lc -93.8 | Preferred for body text |
| Black text on #663B74 | 2.44:1 | Fails | Lc 14.7 | Not readable |
| #663B74 text on white | 8.59:1 | AAA | Lc 89.3 | Fine for body text |
| #663B74 text on black | 2.44:1 | Fails | Lc -12.9 | 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
#F8F4F9
oklch(97.2% 0.008 319.4)
-
Step 100
100
#EFE6F2
oklch(93.5% 0.019 317.7)
-
Step 200
200
#E3D3E8
oklch(88.6% 0.033 318.1)
-
Step 300
300
#D1B5DB
oklch(80.9% 0.061 317.1)
-
Step 400
400
#B98EC8
oklch(70.7% 0.095 317.2)
-
Step 500
500
#A870BA
oklch(63.1% 0.124 317.7)
-
Step 600
600
#9357A6
oklch(55.6% 0.134 317.6)
-
Step 700
700
#7D478E
oklch(49.1% 0.124 317.6)
-
Step 800
800 (this color)
#663B74
oklch(42.8% 0.103 317.4)
-
Step 900
900
#53335D
oklch(37.8% 0.08 317.8)
-
Step 950
950
#311E37
oklch(27.1% 0.052 317.8)
#663B74 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) | #314976 | 0.090 |
| Deuteranopia (no green cones) | #3D4D72 | 0.081 |
| Tritanopia (no blue cones) | #664352 | 0.067 |
| Achromatopsia (no color) | #4C4C4C | 0.104 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #663B74
#663B74
oklch(42.8% 0.103 317.4)
- #315C1E
#315C1E
oklch(42.9% 0.104 137.4)
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 #663B74, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.066
- Dark Slate Blue #483D8B ΔE 0.067
- Twilight #4E518B ΔE 0.071
- Dusk #4E5481 ΔE 0.074
- Light Eggplant #894585 ΔE 0.078
- Brownish Purple #76424E ΔE 0.079
- Blueberry #464196 ΔE 0.079
- Dusty Grape #545775 ΔE 0.081
Use #663B74 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.