#3731BC#3731BC

#3731BC is a dark, highly saturated blue. Relative luminance 0.066; OKLCH L 42.5% C 0.207 H 274.9°. Best body text is #FFFFFF at 9.02:1 contrast (WCAG AA passes).

Color values

HEX	#3731BC
RGB	rgb(55, 49, 188)
HSL	hsl(243, 59%, 46%)
HSV	hsv(243, 74%, 74%)
CMYK	cmyk(70.7%, 73.9%, 0%, 26.3%)
CIE-LAB	lab(30.97, 46.61, -71.47)
CIE-LCH	lch(30.97, 85.33, 303.11°)
OKLab	oklab(42.49% 0.0177 -0.2067)
OKLCH	oklch(42.49% 0.207 274.9)
XYZ	xyz(11.7480, 6.6386, 48.2294)
Luminance	0.0664 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Sapphire (survey)

#2138AB

ΔE00 4.24

Blue With A Hint Of Purple

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#3731BC #B6BC31

analogous

#3171BC #3731BC #7D31BC

triadic

#3731BC #BC3731 #31BC37

tetradic

#3731BC #BC3171 #B6BC31 #31BC7D

square

#3731BC #BC3171 #B6BC31 #31BC7D

split-complementary

#3731BC #BC7D31 #71BC31

monochromatic

#1B185B #29248B #3731BC #5C57D3 #8B88E0

Accessibility & contrast

On white

9.02

#3731BC on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

2.33

#3731BC on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #3731BC

9.02:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3731BC	#FFFFFF	#000000	##FFFFFF
##3731BC	1.00	9.02	2.33	9.02
#FFFFFF	9.02	1.00	21.00	1.00
#000000	2.33	21.00	1.00	21.00
##FFFFFF	9.02	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#004FC0

Deuteranopia (green-blind)

#0042BA

Tritanopia (blue-blind)

#005974

Achromatopsia (no color)

#494949

Design tokens & code

CSS

--color: #3731bc;
/* rgb */ color: rgb(55, 49, 188);
/* oklch */ color: oklch(42.5% 0.207 274.9);

Tailwind

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

SCSS

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

JSON

{
  "hex": "#3731bc",
  "rgb": {
    "r": 55,
    "g": 49,
    "b": 188
  },
  "hsl": {
    "h": 242.59,
    "s": 58.65,
    "l": 46.471
  },
  "oklch": {
    "l": 0.42489,
    "c": 0.20742,
    "h": 274.9
  },
  "luminance": 0.0664
}

Semantic roles & 50–950 ramp

primary

#3731BC

secondary

#C6CA7F

accent

#E246DB

background

#F8F6FD

surface

#F0EBFA

border

#CBC6D3

text

#0C0714

muted

#7D7A83

Preview Lab

Preview with #3731BC

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

Preview Lab → · Contrast checker → · Palette generator →