#1F378B#1F378B

#1F378B is a dark, vivid blue. Relative luminance 0.049; OKLCH L 37.4% C 0.143 H 266.9°. Best body text is #FFFFFF at 10.62:1 contrast (WCAG AA passes).

Color values

HEX	#1F378B
RGB	rgb(31, 55, 139)
HSL	hsl(227, 64%, 33%)
HSV	hsv(227, 78%, 55%)
CMYK	cmyk(77.7%, 60.4%, 0%, 45.5%)
CIE-LAB	lab(26.41, 22.60, -49.37)
CIE-LCH	lch(26.41, 54.30, 294.60°)
OKLab	oklab(37.41% -0.0076 -0.1426)
OKLCH	oklch(37.41% 0.143 266.9)
XYZ	xyz(6.5898, 4.8870, 25.0171)
Luminance	0.0489 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#1F378B #8B731F

analogous

#1F6D8B #1F378B #3D1F8B

triadic

#1F378B #8B1F37 #378B1F

tetradic

#1F378B #8B1F6D #8B731F #1F8B3D

square

#1F378B #8B1F6D #8B731F #1F8B3D

split-complementary

#1F378B #8B3D1F #6D8B1F

monochromatic

#090F27 #142359 #1F378B #2A4BBD #4D6CD7

Accessibility & contrast

On white

10.62

#1F378B on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

1.98

#1F378B on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #1F378B

10.62:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##1F378B	#FFFFFF	#000000	##FFFFFF
##1F378B	1.00	10.62	1.98	10.62
#FFFFFF	10.62	1.00	21.00	1.00
#000000	1.98	21.00	1.00	21.00
##FFFFFF	10.62	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#00448E

Deuteranopia (green-blind)

#003A89

Tritanopia (blue-blind)

#004C5B

Achromatopsia (no color)

#3E3E3E

Design tokens & code

CSS

--color: #1f378b;
/* rgb */ color: rgb(31, 55, 139);
/* oklch */ color: oklch(37.4% 0.143 266.9);

Tailwind

colors: {
  custom: {
    50: '#6c6dae',
    500: '#1f378b',
    950: '#000000',
  },
}

SCSS

$custom: #1f378b;
$custom-light: #6c6dae;
$custom-dark: #000000;

JSON

{
  "hex": "#1f378b",
  "rgb": {
    "r": 31,
    "g": 55,
    "b": 139
  },
  "hsl": {
    "h": 226.667,
    "s": 63.529,
    "l": 33.333
  },
  "oklch": {
    "l": 0.37412,
    "c": 0.14278,
    "h": 266.9
  },
  "luminance": 0.04888
}

Semantic roles & 50–950 ramp

primary

#1F378B

secondary

#BAA24C

accent

#C241E7

background

#F7F6FA

surface

#EDEBF4

border

#C8C6CE

text

#080710

muted

#7B7A7F

Preview Lab

Preview with #1F378B

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

Preview Lab → · Contrast checker → · Palette generator →