Windows Blue#3778BF

#3778BF is a mid, vivid cyan. Relative luminance 0.180; OKLCH L 56.5% C 0.129 H 252.8°. Best body text is #000000 at 4.60:1 contrast (WCAG AA passes).

Windows Blue — editorial page

Color values

HEX	#3778BF
RGB	rgb(55, 120, 191)
HSL	hsl(211, 55%, 48%)
HSV	hsv(211, 71%, 75%)
CMYK	cmyk(71.2%, 37.2%, 0%, 25.1%)
CIE-LAB	lab(49.50, 3.15, -43.22)
CIE-LCH	lch(49.50, 43.33, 274.17°)
OKLab	oklab(56.49% -0.0381 -0.123)
OKLCH	oklch(56.49% 0.129 252.8)
XYZ	xyz(17.6925, 18.0048, 51.8230)
Luminance	0.1801 (WCAG relative)
Temperature	cool
Family	cyan

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#3778BF #BF7E37

analogous

#37BCBF #3778BF #3A37BF

triadic

#3778BF #BF3778 #78BF37

tetradic

#3778BF #BF37BC #BF7E37 #37BF3A

square

#3778BF #BF37BC #BF7E37 #37BF3A

split-complementary

#3778BF #BF3A37 #BCBF37

monochromatic

#1C3C60 #295A8F #3778BF #6297D2 #91B6DF

Accessibility & contrast

On white

4.56

#3778BF on #FFFFFF

AA ✓AA large ✓AAA ✗

On black

4.60

#3778BF on #000000

AA ✓AA large ✓AAA ✗

Best text color

#000000 on #3778BF

4.60:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3778BF	#FFFFFF	#000000	##000000
##3778BF	1.00	4.56	4.60	4.60
#FFFFFF	4.56	1.00	21.00	21.00
#000000	4.60	21.00	1.00	1.00
##000000	4.60	21.00	1.00	1.00

Color blindness preview

Protanopia (red-blind)

#587DC2

Deuteranopia (green-blind)

#4370BE

Tritanopia (blue-blind)

#008992

Achromatopsia (no color)

#767676

Design tokens & code

CSS

--color: #3778bf;
/* rgb */ color: rgb(55, 120, 191);
/* oklch */ color: oklch(56.5% 0.129 252.8);

Tailwind

colors: {
  custom: {
    50: '#7e9ed2',
    500: '#3778bf',
    950: '#000000',
  },
}

SCSS

$custom: #3778bf;
$custom-light: #7e9ed2;
$custom-dark: #000000;

JSON

{
  "hex": "#3778bf",
  "rgb": {
    "r": 55,
    "g": 120,
    "b": 191
  },
  "hsl": {
    "h": 211.324,
    "s": 55.285,
    "l": 48.235
  },
  "oklch": {
    "l": 0.56492,
    "c": 0.12875,
    "h": 252.8
  },
  "luminance": 0.18007
}

Semantic roles & 50–950 ramp

primary

#3778BF

secondary

#CAAA88

accent

#9749DF

background

#F8F9FC

surface

#EFF2F9

border

#CACCD2

text

#0B0E14

muted

#7C7E82

Preview Lab

Preview with #3778BF

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

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