#66639B
Closest named color: Dusky Blue (#475F94). oklch(52.6% 0.087 285.4), rgb(102, 99, 155).
Aa
White text reads best on this color (5.49:1).
About this color
#66639B is a medium-dark, moderately saturated purple. In OKLCH its lightness is 53%, its chroma 0.087 and its hue 285°. Its hue sits on the cool side of the wheel. The nearest named color is Dusky Blue (#475F94), ΔE 0.048 away. White text reads best on it, at 5.49:1.
| Hue family | Purples |
| Lightness | medium-dark (53%) |
| Chroma | moderately saturated (0.087) |
| Temperature | cool |
| Nearest name | Dusky Blue (#475F94) |
| Black text | 3.82:1 |
| White text | 5.49:1 |
Values
| HEX | #66639B |
| RGB | rgb(102, 99, 155) |
| HSL | hsl(243, 22%, 50%) |
| OKLCH | oklch(52.6% 0.087 285.4) |
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 #66639B | 5.49:1 | AA | Lc -82.7 | Fine for body text |
| Black text on #66639B | 3.82:1 | AA large text | Lc 26.7 | Dividers and decoration only |
| #66639B text on white | 5.49:1 | AA | Lc 77.4 | Fine for body text |
| #66639B text on black | 3.82:1 | AA large text | Lc -24.4 | 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
#E9E9F1
oklch(93.6% 0.011 286.2)
-
Step 200
200
#D7D7E7
oklch(88.4% 0.022 285.9)
-
Step 300
300
#BEBEDA
oklch(81% 0.039 285.5)
-
Step 400
400
#9C9CC7
oklch(70.8% 0.062 284.7)
-
Step 500
500
#8483B8
oklch(63.1% 0.079 284.8)
-
Step 600
600 (this color)
#66639B
oklch(52.6% 0.087 285.4)
-
Step 700
700
#5C5A8D
oklch(49.2% 0.081 284.8)
-
Step 800
800
#4B4972
oklch(42.6% 0.067 285.4)
-
Step 900
900
#3F3E5C
oklch(37.8% 0.051 285.2)
-
Step 950
950
#252436
oklch(27% 0.033 286.5)
#66639B 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) | #526B9D | 0.033 |
| Deuteranopia (no green cones) | #51679A | 0.031 |
| Tritanopia (no blue cones) | #586D78 | 0.074 |
| Achromatopsia (no color) | #696969 | 0.087 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66639B
#66639B
oklch(52.6% 0.087 285.4)
- #726E2C
#726E2C
oklch(52.8% 0.087 105.8)
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 #66639B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusky Blue #475F94 ΔE 0.048
- French Blue #436BAD ΔE 0.052
- Muted Purple #805B87 ΔE 0.052
- Dark Lavender #856798 ΔE 0.053
- Dusty Purple #825F87 ΔE 0.053
- Dull Blue #49759C ΔE 0.059
- Muted Blue #3B719F ΔE 0.061
- Metallic Blue #4F738E ΔE 0.062
Use #66639B 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.