#3666BC#3666BC

#3666BC is a mid, vivid blue. Relative luminance 0.139; OKLCH L 52.2% C 0.145 H 261.0°. Best body text is #FFFFFF at 5.55:1 contrast (WCAG AA passes).

Color values

HEX	#3666BC
RGB	rgb(54, 102, 188)
HSL	hsl(219, 55%, 47%)
HSV	hsv(219, 71%, 74%)
CMYK	cmyk(71.3%, 45.7%, 0%, 26.3%)
CIE-LAB	lab(44.11, 13.16, -50.08)
CIE-LCH	lch(44.11, 51.78, 284.72°)
OKLab	oklab(52.25% -0.0226 -0.1434)
OKLCH	oklch(52.25% 0.145 261)
XYZ	xyz(15.3465, 13.9162, 49.4445)
Luminance	0.1392 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#3666BC #BC8C36

analogous

#36A9BC #3666BC #4936BC

triadic

#3666BC #BC3666 #66BC36

tetradic

#3666BC #BC36A9 #BC8C36 #36BC49

square

#3666BC #BC36A9 #BC8C36 #36BC49

split-complementary

#3666BC #BC4936 #A9BC36

monochromatic

#1B325D #284C8C #3666BC #5E87D1 #8EABDF

Accessibility & contrast

On white

5.55

#3666BC on #FFFFFF

AA ✓AA large ✓AAA ✗

On black

3.78

#3666BC on #000000

AA ✗AA large ✓AAA ✗

Best text color

#FFFFFF on #3666BC

5.55:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3666BC	#FFFFFF	#000000	##FFFFFF
##3666BC	1.00	5.55	3.78	5.55
#FFFFFF	5.55	1.00	21.00	1.00
#000000	3.78	21.00	1.00	21.00
##FFFFFF	5.55	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#3A6FBF

Deuteranopia (green-blind)

#1E63BA

Tritanopia (blue-blind)

#007A88

Achromatopsia (no color)

#686868

Design tokens & code

CSS

--color: #3666bc;
/* rgb */ color: rgb(54, 102, 188);
/* oklch */ color: oklch(52.2% 0.145 261.0);

Tailwind

colors: {
  custom: {
    50: '#7d91d1',
    500: '#3666bc',
    950: '#000000',
  },
}

SCSS

$custom: #3666bc;
$custom-light: #7d91d1;
$custom-dark: #000000;

JSON

{
  "hex": "#3666bc",
  "rgb": {
    "r": 54,
    "g": 102,
    "b": 188
  },
  "hsl": {
    "h": 218.507,
    "s": 55.372,
    "l": 47.451
  },
  "oklch": {
    "l": 0.52245,
    "c": 0.14522,
    "h": 261
  },
  "luminance": 0.13918
}

Semantic roles & 50–950 ramp

primary

#3666BC

secondary

#C9B185

accent

#A949DF

background

#F8F8FC

surface

#EFF0F9

border

#CACBD2

text

#0B0C14

muted

#7C7D82

Preview Lab

Preview with #3666BC

Body copy rendered with the generated semantic roles for this colour.

Preview Lab → · Contrast checker → · Palette generator →