#3731BB#3731BB

#3731BB is a dark, highly saturated blue. Relative luminance 0.066; OKLCH L 42.4% C 0.206 H 275.0°. Best body text is #FFFFFF at 9.05:1 contrast (WCAG AA passes).

Color values

HEX	#3731BB
RGB	rgb(55, 49, 187)
HSL	hsl(243, 58%, 46%)
HSV	hsv(243, 74%, 73%)
CMYK	cmyk(70.6%, 73.8%, 0%, 26.7%)
CIE-LAB	lab(30.87, 46.29, -71.05)
CIE-LCH	lch(30.87, 84.80, 303.08°)
OKLab	oklab(42.39% 0.0179 -0.2054)
OKLCH	oklch(42.39% 0.206 275)
XYZ	xyz(11.6405, 6.5956, 47.6637)
Luminance	0.0660 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Sapphire (survey)

#2138AB

ΔE00 4.17

Blue With A Hint Of Purple

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#3731BB #B5BB31

analogous

#3170BB #3731BB #7C31BB

triadic

#3731BB #BB3731 #31BB37

tetradic

#3731BB #BB3170 #B5BB31 #31BB7C

square

#3731BB #BB3170 #B5BB31 #31BB7C

split-complementary

#3731BB #BB7C31 #70BB31

monochromatic

#1A185A #29248B #3731BB #5C56D3 #8B87E0

Accessibility & contrast

On white

9.05

#3731BB on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

2.32

#3731BB on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #3731BB

9.05:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3731BB	#FFFFFF	#000000	##FFFFFF
##3731BB	1.00	9.05	2.32	9.05
#FFFFFF	9.05	1.00	21.00	1.00
#000000	2.32	21.00	1.00	21.00
##FFFFFF	9.05	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#004FBF

Deuteranopia (green-blind)

#0042B9

Tritanopia (blue-blind)

#005973

Achromatopsia (no color)

#494949

Design tokens & code

CSS

--color: #3731bb;
/* rgb */ color: rgb(55, 49, 187);
/* oklch */ color: oklch(42.4% 0.206 275.0);

Tailwind

colors: {
  custom: {
    50: '#816bd1',
    500: '#3731bb',
    950: '#000000',
  },
}

SCSS

$custom: #3731bb;
$custom-light: #816bd1;
$custom-dark: #000000;

JSON

{
  "hex": "#3731bb",
  "rgb": {
    "r": 55,
    "g": 49,
    "b": 187
  },
  "hsl": {
    "h": 242.609,
    "s": 58.475,
    "l": 46.275
  },
  "oklch": {
    "l": 0.42387,
    "c": 0.20621,
    "h": 275
  },
  "luminance": 0.06597
}

Semantic roles & 50–950 ramp

primary

#3731BB

secondary

#C6C97F

accent

#E246DB

background

#F8F6FD

surface

#F0EBFA

border

#CBC6D3

text

#0C0714

muted

#7D7A83

Preview Lab

Preview with #3731BB

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

Preview Lab → · Contrast checker → · Palette generator →