#6566E2
Closest named color: Dark Periwinkle (#665FD1). oklch(57.6% 0.184 278.6), rgb(101, 102, 226).
Aa
White text reads best on this color (4.61:1).
About this color
#6566E2 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.184 and its hue 279°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.029 away. White text reads best on it, at 4.61:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.184) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.55:1 |
| White text | 4.61:1 |
Values
| HEX | #6566E2 |
| RGB | rgb(101, 102, 226) |
| HSL | hsl(240, 68%, 64%) |
| OKLCH | oklch(57.6% 0.184 278.6) |
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 #6566E2 | 4.61:1 | AA | Lc -77.2 | Fine for body text |
| Black text on #6566E2 | 4.55:1 | AA | Lc 32.4 | Non-text elements, placeholder text |
| #6566E2 text on white | 4.61:1 | AA | Lc 71.7 | Content text, not long reading |
| #6566E2 text on black | 4.55:1 | AA | Lc -30.0 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E6E9FA
oklch(93.7% 0.023 277.9)
-
Step 200
200
#D2D7F8
oklch(88.6% 0.046 278.6)
-
Step 300
300
#B4BCF6
oklch(80.9% 0.082 278.3)
-
Step 400
400
#8F97F2
oklch(70.8% 0.133 278.6)
-
Step 500
500
#757AED
oklch(63.1% 0.169 278.5)
-
Step 600
600 (this color)
#6566E2
oklch(57.6% 0.184 278.6)
-
Step 700
700
#504EBE
oklch(49.1% 0.171 278.8)
-
Step 800
800
#41419A
oklch(42.8% 0.142 278.6)
-
Step 900
900
#36387A
oklch(37.7% 0.11 278.4)
-
Step 950
950
#202148
oklch(27% 0.071 279.4)
#6566E2 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) | #0D7AE6 | 0.077 |
| Deuteranopia (no green cones) | #0070DF | 0.076 |
| Tritanopia (no blue cones) | #24839A | 0.160 |
| Achromatopsia (no color) | #757575 | 0.184 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6566E2
#6566E2
oklch(57.6% 0.184 278.6)
- #8B7900
#8B7900
oklch(57.5% 0.119 98.8)
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 #6566E2, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.029
- Medium Slate Blue #7B68EE ΔE 0.038
- Light Indigo #6D5ACF ΔE 0.039
- Slate Blue #6A5ACD ΔE 0.041
- Royal Blue #4169E1 ΔE 0.043
- Neon Blue #4361EE ΔE 0.049
- Warm Blue #4B57DB ΔE 0.054
- Cornflower #6A79F7 ΔE 0.054
Use #6566E2 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.