#173F8C#173F8C

#173F8C is a dark, vivid blue. Relative luminance 0.056; OKLCH L 38.9% C 0.136 H 261.8°. Best body text is #FFFFFF at 9.88:1 contrast (WCAG AA passes).

Color values

HEX	#173F8C
RGB	rgb(23, 63, 140)
HSL	hsl(219, 72%, 32%)
HSV	hsv(219, 84%, 55%)
CMYK	cmyk(83.6%, 55%, 0%, 45.1%)
CIE-LAB	lab(28.46, 16.57, -46.68)
CIE-LCH	lch(28.46, 49.53, 289.55°)
OKLab	oklab(38.9% -0.0195 -0.1346)
OKLCH	oklch(38.9% 0.136 261.8)
XYZ	xyz(6.8628, 5.6298, 25.5308)
Luminance	0.0563 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#173F8C #8C6417

analogous

#177A8C #173F8C #2A178C

triadic

#173F8C #8C173F #3F8C17

tetradic

#173F8C #8C177A #8C6417 #178C2A

square

#173F8C #8C177A #8C6417 #178C2A

split-complementary

#173F8C #8C2A17 #7A8C17

monochromatic

#061023 #0E2757 #173F8C #2057C1 #3E75DF

Accessibility & contrast

On white

9.88

#173F8C on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

2.13

#173F8C on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #173F8C

9.88:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##173F8C	#FFFFFF	#000000	##FFFFFF
##173F8C	1.00	9.88	2.13	9.88
#FFFFFF	9.88	1.00	21.00	1.00
#000000	2.13	21.00	1.00	21.00
##FFFFFF	9.88	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#00498F

Deuteranopia (green-blind)

#003E8A

Tritanopia (blue-blind)

#00525F

Achromatopsia (no color)

#434343

Design tokens & code

CSS

--color: #173f8c;
/* rgb */ color: rgb(23, 63, 140);
/* oklch */ color: oklch(38.9% 0.136 261.8);

Tailwind

colors: {
  custom: {
    50: '#6973ae',
    500: '#173f8c',
    950: '#000000',
  },
}

SCSS

$custom: #173f8c;
$custom-light: #6973ae;
$custom-dark: #000000;

JSON

{
  "hex": "#173f8c",
  "rgb": {
    "r": 23,
    "g": 63,
    "b": 140
  },
  "hsl": {
    "h": 219.487,
    "s": 71.779,
    "l": 31.961
  },
  "oklch": {
    "l": 0.38896,
    "c": 0.13604,
    "h": 261.8
  },
  "luminance": 0.05631
}

Semantic roles & 50–950 ramp

primary

#173F8C

secondary

#BF943F

accent

#B139EF

background

#F6F6FA

surface

#ECECF4

border

#C7C7CE

text

#070810

muted

#7A7B7F

Preview Lab

Preview with #173F8C

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

Preview Lab → · Contrast checker → · Palette generator →