#183F5B#183F5B

#183F5B is a dark, moderate cyan. Relative luminance 0.045; OKLCH L 35.4% C 0.066 H 243.0°. Best body text is #FFFFFF at 11.05:1 contrast (WCAG AA passes).

Color values

HEX	#183F5B
RGB	rgb(24, 63, 91)
HSL	hsl(205, 58%, 23%)
HSV	hsv(205, 74%, 36%)
CMYK	cmyk(73.6%, 30.8%, 0%, 64.3%)
CIE-LAB	lab(25.27, -3.38, -20.71)
CIE-LCH	lch(25.27, 20.98, 260.74°)
OKLab	oklab(35.4% -0.0298 -0.0584)
OKLCH	oklch(35.4% 0.066 243)
XYZ	xyz(4.0418, 4.5041, 10.5519)
Luminance	0.0450 (WCAG relative)
Temperature	cool
Family	cyan

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#183F5B #5B3418

analogous

#185B56 #183F5B #181D5B

triadic

#183F5B #5B183F #3F5B18

tetradic

#183F5B #56185B #5B3418 #1D5B18

square

#183F5B #56185B #5B3418 #1D5B18

split-complementary

#183F5B #5B181D #5B5618

monochromatic

#061118 #0B1D2B #183F5B #25618B #3282BC

Accessibility & contrast

On white

11.05

#183F5B on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

1.90

#183F5B on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #183F5B

11.05:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##183F5B	#FFFFFF	#000000	##FFFFFF
##183F5B	1.00	11.05	1.90	11.05
#FFFFFF	11.05	1.00	21.00	1.00
#000000	1.90	21.00	1.00	21.00
##FFFFFF	11.05	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#32405C

Deuteranopia (green-blind)

#29395A

Tritanopia (blue-blind)

#004649

Achromatopsia (no color)

#3C3C3C

Design tokens & code

CSS

--color: #183f5b;
/* rgb */ color: rgb(24, 63, 91);
/* oklch */ color: oklch(35.4% 0.066 243.0);

Tailwind

colors: {
  custom: {
    50: '#5e7389',
    500: '#183f5b',
    950: '#000000',
  },
}

SCSS

$custom: #183f5b;
$custom-light: #5e7389;
$custom-dark: #000000;

JSON

{
  "hex": "#183f5b",
  "rgb": {
    "r": 24,
    "g": 63,
    "b": 91
  },
  "hsl": {
    "h": 205.075,
    "s": 58.261,
    "l": 22.549
  },
  "oklch": {
    "l": 0.35402,
    "c": 0.0656,
    "h": 243
  },
  "luminance": 0.04505
}

Semantic roles & 50–950 ramp

primary

#183F5B

secondary

#92603D

accent

#8746E1

background

#F5F7F8

surface

#E9EDF0

border

#C5C8CB

text

#05080B

muted

#797B7C

Preview Lab

Preview with #183F5B

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

Preview Lab → · Contrast checker → · Palette generator →