#173B8B#173B8B

#173B8B is a dark, vivid blue. Relative luminance 0.052; OKLCH L 37.9% C 0.140 H 263.1°. Best body text is #FFFFFF at 10.32:1 contrast (WCAG AA passes).

Color values

HEX	#173B8B
RGB	rgb(23, 59, 139)
HSL	hsl(221, 72%, 32%)
HSV	hsv(221, 83%, 55%)
CMYK	cmyk(83.5%, 57.6%, 0%, 45.5%)
CIE-LAB	lab(27.22, 18.95, -48.06)
CIE-LCH	lch(27.22, 51.67, 291.52°)
OKLab	oklab(37.94% -0.0167 -0.1388)
OKLCH	oklch(37.94% 0.14 263.1)
XYZ	xyz(6.5758, 5.1734, 25.0731)
Luminance	0.0517 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#173B8B #8B6717

analogous

#17758B #173B8B #2D178B

triadic

#173B8B #8B173B #3B8B17

tetradic

#173B8B #8B1775 #8B6717 #178B2D

square

#173B8B #8B1775 #8B6717 #178B2D

split-complementary

#173B8B #8B2D17 #758B17

monochromatic

#060E22 #0E2556 #173B8B #2051C0 #3D70DF

Accessibility & contrast

On white

10.32

#173B8B on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

2.03

#173B8B on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #173B8B

10.32:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##173B8B	#FFFFFF	#000000	##FFFFFF
##173B8B	1.00	10.32	2.03	10.32
#FFFFFF	10.32	1.00	21.00	1.00
#000000	2.03	21.00	1.00	21.00
##FFFFFF	10.32	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#00468E

Deuteranopia (green-blind)

#003B89

Tritanopia (blue-blind)

#004F5D

Achromatopsia (no color)

#404040

Design tokens & code

CSS

--color: #173b8b;
/* rgb */ color: rgb(23, 59, 139);
/* oklch */ color: oklch(37.9% 0.140 263.1);

Tailwind

colors: {
  custom: {
    50: '#6970ae',
    500: '#173b8b',
    950: '#000000',
  },
}

SCSS

$custom: #173b8b;
$custom-light: #6970ae;
$custom-dark: #000000;

JSON

{
  "hex": "#173b8b",
  "rgb": {
    "r": 23,
    "g": 59,
    "b": 139
  },
  "hsl": {
    "h": 221.379,
    "s": 71.605,
    "l": 31.765
  },
  "oklch": {
    "l": 0.37936,
    "c": 0.13981,
    "h": 263.1
  },
  "luminance": 0.05174
}

Semantic roles & 50–950 ramp

primary

#173B8B

secondary

#BF973F

accent

#B639EE

background

#F6F6FA

surface

#ECECF4

border

#C7C7CE

text

#070710

muted

#7A7A7F

Preview Lab

Preview with #173B8B

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

Preview Lab → · Contrast checker → · Palette generator →