#1B3583#1B3583

#1B3583 is a dark, vivid blue. Relative luminance 0.044; OKLCH L 36.1% C 0.135 H 265.8°. Best body text is #FFFFFF at 11.15:1 contrast (WCAG AA passes).

Color values

HEX	#1B3583
RGB	rgb(27, 53, 131)
HSL	hsl(225, 66%, 31%)
HSV	hsv(225, 79%, 51%)
CMYK	cmyk(79.4%, 59.5%, 0%, 48.6%)
CIE-LAB	lab(25.01, 20.33, -46.69)
CIE-LCH	lch(25.01, 50.92, 293.53°)
OKLab	oklab(36.1% -0.0099 -0.1348)
OKLCH	oklch(36.1% 0.135 265.8)
XYZ	xyz(5.8204, 4.4173, 22.0142)
Luminance	0.0442 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#1B3583 #83691B

analogous

#1B6983 #1B3583 #351B83

triadic

#1B3583 #831B35 #35831B

tetradic

#1B3583 #831B69 #83691B #1B8335

square

#1B3583 #831B69 #83691B #1B8335

split-complementary

#1B3583 #83351B #69831B

monochromatic

#060C1E #112050 #1B3583 #254AB6 #4166D8

Accessibility & contrast

On white

11.15

#1B3583 on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

1.88

#1B3583 on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #1B3583

11.15:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##1B3583	#FFFFFF	#000000	##FFFFFF
##1B3583	1.00	11.15	1.88	11.15
#FFFFFF	11.15	1.00	21.00	1.00
#000000	1.88	21.00	1.00	21.00
##FFFFFF	11.15	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#004086

Deuteranopia (green-blind)

#003781

Tritanopia (blue-blind)

#004956

Achromatopsia (no color)

#3B3B3B

Design tokens & code

CSS

--color: #1b3583;
/* rgb */ color: rgb(27, 53, 131);
/* oklch */ color: oklch(36.1% 0.135 265.8);

Tailwind

colors: {
  custom: {
    50: '#696ba8',
    500: '#1b3583',
    950: '#000000',
  },
}

SCSS

$custom: #1b3583;
$custom-light: #696ba8;
$custom-dark: #000000;

JSON

{
  "hex": "#1b3583",
  "rgb": {
    "r": 27,
    "g": 53,
    "b": 131
  },
  "hsl": {
    "h": 225,
    "s": 65.823,
    "l": 30.98
  },
  "oklch": {
    "l": 0.36102,
    "c": 0.13515,
    "h": 265.8
  },
  "luminance": 0.04418
}

Semantic roles & 50–950 ramp

primary

#1B3583

secondary

#B69A43

accent

#BE3FE9

background

#F6F6FA

surface

#ECEBF4

border

#C7C6CE

text

#070610

muted

#7A7A7F

Preview Lab

Preview with #1B3583

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

Preview Lab → · Contrast checker → · Palette generator →