#173F8B#173F8B

#173F8B is a dark, vivid blue. Relative luminance 0.056; OKLCH L 38.8% C 0.135 H 261.6°. Best body text is #FFFFFF at 9.90:1 contrast (WCAG AA passes).

Color values

HEX	#173F8B
RGB	rgb(23, 63, 139)
HSL	hsl(219, 72%, 32%)
HSV	hsv(219, 83%, 55%)
CMYK	cmyk(83.5%, 54.7%, 0%, 45.5%)
CIE-LAB	lab(28.38, 16.16, -46.18)
CIE-LCH	lch(28.38, 48.93, 289.29°)
OKLab	oklab(38.81% -0.0196 -0.1332)
OKLCH	oklch(38.81% 0.135 261.6)
XYZ	xyz(6.7894, 5.6004, 25.1443)
Luminance	0.0560 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#173F8B #8B6317

analogous

#17798B #173F8B #29178B

triadic

#173F8B #8B173F #3F8B17

tetradic

#173F8B #8B1779 #8B6317 #178B29

square

#173F8B #8B1779 #8B6317 #178B29

split-complementary

#173F8B #8B2917 #798B17

monochromatic

#060F22 #0E2756 #173F8B #2057C0 #3D75DF

Accessibility & contrast

On white

9.90

#173F8B on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

2.12

#173F8B on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #173F8B

9.90:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##173F8B	#FFFFFF	#000000	##FFFFFF
##173F8B	1.00	9.90	2.12	9.90
#FFFFFF	9.90	1.00	21.00	1.00
#000000	2.12	21.00	1.00	21.00
##FFFFFF	9.90	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#02488E

Deuteranopia (green-blind)

#003E8A

Tritanopia (blue-blind)

#00525E

Achromatopsia (no color)

#434343

Design tokens & code

CSS

--color: #173f8b;
/* rgb */ color: rgb(23, 63, 139);
/* oklch */ color: oklch(38.8% 0.135 261.6);

Tailwind

colors: {
  custom: {
    50: '#6973ad',
    500: '#173f8b',
    950: '#000000',
  },
}

SCSS

$custom: #173f8b;
$custom-light: #6973ad;
$custom-dark: #000000;

JSON

{
  "hex": "#173f8b",
  "rgb": {
    "r": 23,
    "g": 63,
    "b": 139
  },
  "hsl": {
    "h": 219.31,
    "s": 71.605,
    "l": 31.765
  },
  "oklch": {
    "l": 0.38813,
    "c": 0.13462,
    "h": 261.6
  },
  "luminance": 0.05601
}

Semantic roles & 50–950 ramp

primary

#173F8B

secondary

#BF933F

accent

#B039EE

background

#F6F6FA

surface

#ECECF4

border

#C7C7CE

text

#070810

muted

#7A7B7F

Preview Lab

Preview with #173F8B

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

Preview Lab → · Contrast checker → · Palette generator →