#6566CD
Closest named color: Dark Periwinkle (#665FD1). oklch(56.1% 0.155 279.7), rgb(101, 102, 205).
Aa
White text reads best on this color (4.84:1).
About this color
#6566CD is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.155 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.019 away. White text reads best on it, at 4.84:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.155) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.33:1 |
| White text | 4.84:1 |
Values
| HEX | #6566CD |
| RGB | rgb(101, 102, 205) |
| HSL | hsl(239, 51%, 60%) |
| OKLCH | oklch(56.1% 0.155 279.7) |
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 #6566CD | 4.84:1 | AA | Lc -78.8 | Fine for body text |
| Black text on #6566CD | 4.33:1 | AA large text | Lc 30.7 | Non-text elements, placeholder text |
| #6566CD text on white | 4.84:1 | AA | Lc 73.4 | Content text, not long reading |
| #6566CD text on black | 4.33:1 | AA large text | Lc -28.3 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E7E9F8
oklch(93.7% 0.02 279.9)
-
Step 200
200
#D3D7F3
oklch(88.5% 0.039 279.1)
-
Step 300
300
#B7BCEE
oklch(80.8% 0.071 280.2)
-
Step 400
400
#9398E5
oklch(70.6% 0.112 280.3)
-
Step 500
500
#797DDE
oklch(63.1% 0.144 279.6)
-
Step 600
600 (this color)
#6566CD
oklch(56.1% 0.155 279.7)
-
Step 700
700
#5353B0
oklch(49.2% 0.144 279.7)
-
Step 800
800
#44448E
oklch(42.7% 0.119 280.1)
-
Step 900
900
#393A72
oklch(37.7% 0.094 280.1)
-
Step 950
950
#212243
oklch(26.9% 0.061 280.2)
#6566CD 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) | #3476D1 | 0.061 |
| Deuteranopia (no green cones) | #2A6ECB | 0.063 |
| Tritanopia (no blue cones) | #3B7D90 | 0.135 |
| Achromatopsia (no color) | #727272 | 0.156 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6566CD
#6566CD
oklch(56.1% 0.155 279.7)
- #857500
#857500
oklch(56% 0.116 99.8)
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 #6566CD, closest first.
No curated palette has a color within ΔE 0.04 of #6566CD.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.019
- Slate Blue #6A5ACD ΔE 0.029
- Light Indigo #6D5ACF ΔE 0.030
- Iris #6258C4 ΔE 0.037
- Royal Blue #4169E1 ΔE 0.052
- Warm Blue #4B57DB ΔE 0.059
- Medium Slate Blue #7B68EE ΔE 0.060
- Neon Blue #4361EE ΔE 0.068
Use #6566CD 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.