#66639E
Closest named color: Dusky Blue (#475F94). oklch(52.8% 0.092 285.1), rgb(102, 99, 158).
Aa
White text reads best on this color (5.46:1).
About this color
#66639E is a medium-dark, moderately saturated purple. In OKLCH its lightness is 53%, its chroma 0.092 and its hue 285°. Its hue sits on the cool side of the wheel. The nearest named color is Dusky Blue (#475F94), ΔE 0.049 away. White text reads best on it, at 5.46:1.
| Hue family | Purples |
| Lightness | medium-dark (53%) |
| Chroma | moderately saturated (0.092) |
| Temperature | cool |
| Nearest name | Dusky Blue (#475F94) |
| Black text | 3.84:1 |
| White text | 5.46:1 |
Values
| HEX | #66639E |
| RGB | rgb(102, 99, 158) |
| HSL | hsl(243, 23%, 50%) |
| OKLCH | oklch(52.8% 0.092 285.1) |
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 #66639E | 5.46:1 | AA | Lc -82.5 | Fine for body text |
| Black text on #66639E | 3.84:1 | AA large text | Lc 26.9 | Dividers and decoration only |
| #66639E text on white | 5.46:1 | AA | Lc 77.2 | Fine for body text |
| #66639E text on black | 3.84:1 | AA large text | Lc -24.6 | Dividers and decoration only |
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 600.
-
Step 50
50
#F5F5F9
oklch(97.1% 0.005 286.3)
-
Step 100
100
#E9E9F2
oklch(93.7% 0.012 286.2)
-
Step 200
200
#D7D7E8
oklch(88.4% 0.023 285.9)
-
Step 300
300
#BDBDDB
oklch(80.8% 0.042 285.4)
-
Step 400
400
#9C9BC9
oklch(70.7% 0.067 285.6)
-
Step 500
500
#8482BB
oklch(63.1% 0.085 285.3)
-
Step 600
600 (this color)
#66639E
oklch(52.8% 0.092 285.1)
-
Step 700
700
#5C598F
oklch(49.1% 0.085 285.3)
-
Step 800
800
#4B4974
oklch(42.7% 0.071 285.1)
-
Step 900
900
#3E3D5E
oklch(37.6% 0.056 284.8)
-
Step 950
950
#252437
oklch(27% 0.035 286.2)
#66639E 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) | #516BA0 | 0.034 |
| Deuteranopia (no green cones) | #4F689D | 0.034 |
| Tritanopia (no blue cones) | #576E79 | 0.079 |
| Achromatopsia (no color) | #696969 | 0.092 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66639E
#66639E
oklch(52.8% 0.092 285.1)
- #736E27
#736E27
oklch(52.8% 0.092 105.3)
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 #66639E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusky Blue #475F94 ΔE 0.049
- French Blue #436BAD ΔE 0.050
- Dark Lavender #856798 ΔE 0.053
- Muted Purple #805B87 ΔE 0.054
- Dusty Purple #825F87 ΔE 0.056
- Dull Blue #49759C ΔE 0.061
- Muted Blue #3B719F ΔE 0.061
- Flat Blue #3C73A8 ΔE 0.062
Use #66639E 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.