#3F78CB#3F78CB

#3F78CB is a mid, vivid blue. Relative luminance 0.188; OKLCH L 57.5% C 0.142 H 257.9°. Best body text is #000000 at 4.76:1 contrast (WCAG AA passes).

Color values

HEX	#3F78CB
RGB	rgb(63, 120, 203)
HSL	hsl(216, 57%, 52%)
HSV	hsv(216, 69%, 80%)
CMYK	cmyk(69%, 40.9%, 0%, 20.4%)
CIE-LAB	lab(50.45, 8.68, -48.56)
CIE-LCH	lch(50.45, 49.33, 280.13°)
OKLab	oklab(57.53% -0.0297 -0.1385)
OKLCH	oklch(57.53% 0.142 257.9)
XYZ	xyz(19.5420, 18.7995, 59.0871)
Luminance	0.1880 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#3F78CB #CB923F

analogous

#3FBECB #3F78CB #4C3FCB

triadic

#3F78CB #CB3F78 #78CB3F

tetradic

#3F78CB #CB3FBE #CB923F #3FCB4C

square

#3F78CB #CB3FBE #CB923F #3FCB4C

split-complementary

#3F78CB #CB4C3F #BECB3F

monochromatic

#1F4071 #2C5BA1 #3F78CB #6F9AD8 #9FBCE5

Accessibility & contrast

On white

4.41

#3F78CB on #FFFFFF

AA ✗AA large ✓AAA ✗

On black

4.76

#3F78CB on #000000

AA ✓AA large ✓AAA ✗

Best text color

#000000 on #3F78CB

4.76:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3F78CB	#FFFFFF	#000000	##000000
##3F78CB	1.00	4.41	4.76	4.76
#FFFFFF	4.41	1.00	21.00	21.00
#000000	4.76	21.00	1.00	1.00
##000000	4.76	21.00	1.00	1.00

Color blindness preview

Protanopia (red-blind)

#517FCE

Deuteranopia (green-blind)

#3B72C9

Tritanopia (blue-blind)

#008B97

Achromatopsia (no color)

#787878

Design tokens & code

CSS

--color: #3f78cb;
/* rgb */ color: rgb(63, 120, 203);
/* oklch */ color: oklch(57.5% 0.142 257.9);

Tailwind

colors: {
  custom: {
    50: '#849edb',
    500: '#3f78cb',
    950: '#000000',
  },
}

SCSS

$custom: #3f78cb;
$custom-light: #849edb;
$custom-dark: #000000;

JSON

{
  "hex": "#3f78cb",
  "rgb": {
    "r": 63,
    "g": 120,
    "b": 203
  },
  "hsl": {
    "h": 215.571,
    "s": 57.377,
    "l": 52.157
  },
  "oklch": {
    "l": 0.57527,
    "c": 0.14167,
    "h": 257.9
  },
  "luminance": 0.18802
}

Semantic roles & 50–950 ramp

primary

#3F78CB

secondary

#D1B994

accent

#A247E1

background

#F8F9FD

surface

#F0F2FB

border

#CBCCD4

text

#0C0E15

muted

#7D7E83

Preview Lab

Preview with #3F78CB

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

Preview Lab → · Contrast checker → · Palette generator →