#6566BB
Closest named color: Dark Periwinkle (#665FD1). oklch(55% 0.13 280.7), rgb(101, 102, 187).
Aa
White text reads best on this color (5.03:1).
About this color
#6566BB is a medium-dark, moderately saturated purple. In OKLCH its lightness is 55%, its chroma 0.130 and its hue 281°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.040 away. White text reads best on it, at 5.03:1.
| Hue family | Purples |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.130) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.17:1 |
| White text | 5.03:1 |
Values
| HEX | #6566BB |
| RGB | rgb(101, 102, 187) |
| HSL | hsl(239, 39%, 56%) |
| OKLCH | oklch(55% 0.13 280.7) |
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 #6566BB | 5.03:1 | AA | Lc -80.0 | Fine for body text |
| Black text on #6566BB | 4.17:1 | AA large text | Lc 29.4 | Dividers and decoration only |
| #6566BB text on white | 5.03:1 | AA | Lc 74.6 | Content text, not long reading |
| #6566BB text on black | 4.17:1 | AA large text | Lc -27.1 | 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
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E7E9F5
oklch(93.6% 0.016 278.5)
-
Step 200
200
#D5D7EF
oklch(88.5% 0.033 281.9)
-
Step 300
300
#B9BDE6
oklch(80.9% 0.058 280.6)
-
Step 400
400
#969ADA
oklch(70.7% 0.093 281)
-
Step 500
500
#7D80D0
oklch(63.2% 0.119 280.8)
-
Step 600
600 (this color)
#6566BB
oklch(55% 0.13 280.7)
-
Step 700
700
#5656A3
oklch(49.1% 0.121 281)
-
Step 800
800
#464784
oklch(42.8% 0.099 280.6)
-
Step 900
900
#3A3C6A
oklch(37.7% 0.078 280.1)
-
Step 950
950
#22233E
oklch(26.9% 0.05 280.9)
#6566BB 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) | #4472BE | 0.047 |
| Deuteranopia (no green cones) | #3E6CB9 | 0.048 |
| Tritanopia (no blue cones) | #487887 | 0.114 |
| Achromatopsia (no color) | #6F6F6F | 0.130 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6566BB
#6566BB
oklch(55% 0.13 280.7)
- #817200
#817200
oklch(54.9% 0.114 100.2)
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 #6566BB, closest first.
No curated palette has a color within ΔE 0.04 of #6566BB.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.040
- Iris #6258C4 ΔE 0.041
- Slate Blue #6A5ACD ΔE 0.044
- Light Indigo #6D5ACF ΔE 0.046
- French Blue #436BAD ΔE 0.051
- Windows Blue #3778BF ΔE 0.064
- Deep Lavender #8D5EB7 ΔE 0.065
- Flat Blue #3C73A8 ΔE 0.069
Use #6566BB 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.