#3666BB#3666BB

#3666BB is a mid, vivid blue. Relative luminance 0.139; OKLCH L 52.2% C 0.144 H 260.9°. Best body text is #FFFFFF at 5.56:1 contrast (WCAG AA passes).

Color values

HEX	#3666BB
RGB	rgb(54, 102, 187)
HSL	hsl(218, 55%, 47%)
HSV	hsv(218, 71%, 73%)
CMYK	cmyk(71.1%, 45.5%, 0%, 26.7%)
CIE-LAB	lab(44.05, 12.79, -49.60)
CIE-LCH	lch(44.05, 51.23, 284.46°)
OKLab	oklab(52.18% -0.0228 -0.142)
OKLCH	oklch(52.18% 0.144 260.9)
XYZ	xyz(15.2391, 13.8733, 48.8788)
Luminance	0.1388 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#3666BB #BB8B36

analogous

#36A9BB #3666BB #4936BB

triadic

#3666BB #BB3666 #66BB36

tetradic

#3666BB #BB36A9 #BB8B36 #36BB49

square

#3666BB #BB36A9 #BB8B36 #36BB49

split-complementary

#3666BB #BB4936 #A9BB36

monochromatic

#1B325C #284C8C #3666BB #5E87D0 #8DAADE

Accessibility & contrast

On white

5.56

#3666BB on #FFFFFF

AA ✓AA large ✓AAA ✗

On black

3.78

#3666BB on #000000

AA ✗AA large ✓AAA ✗

Best text color

#FFFFFF on #3666BB

5.56:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3666BB	#FFFFFF	#000000	##FFFFFF
##3666BB	1.00	5.56	3.78	5.56
#FFFFFF	5.56	1.00	21.00	1.00
#000000	3.78	21.00	1.00	21.00
##FFFFFF	5.56	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#3B6FBE

Deuteranopia (green-blind)

#2062B9

Tritanopia (blue-blind)

#007A87

Achromatopsia (no color)

#686868

Design tokens & code

CSS

--color: #3666bb;
/* rgb */ color: rgb(54, 102, 187);
/* oklch */ color: oklch(52.2% 0.144 260.9);

Tailwind

colors: {
  custom: {
    50: '#7d91d0',
    500: '#3666bb',
    950: '#000000',
  },
}

SCSS

$custom: #3666bb;
$custom-light: #7d91d0;
$custom-dark: #000000;

JSON

{
  "hex": "#3666bb",
  "rgb": {
    "r": 54,
    "g": 102,
    "b": 187
  },
  "hsl": {
    "h": 218.346,
    "s": 55.187,
    "l": 47.255
  },
  "oklch": {
    "l": 0.52177,
    "c": 0.14385,
    "h": 260.9
  },
  "luminance": 0.13875
}

Semantic roles & 50–950 ramp

primary

#3666BB

secondary

#C9B084

accent

#A949DF

background

#F8F8FC

surface

#EFF0F9

border

#CACBD2

text

#0B0C14

muted

#7C7D82

Preview Lab

Preview with #3666BB

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

Preview Lab → · Contrast checker → · Palette generator →