#3F40B3#3F40B3

#3F40B3 is a dark, vivid blue. Relative luminance 0.080; OKLCH L 44.5% C 0.178 H 276.0°. Best body text is #FFFFFF at 8.09:1 contrast (WCAG AA passes).

Color values

HEX	#3F40B3
RGB	rgb(63, 64, 179)
HSL	hsl(239, 48%, 47%)
HSV	hsv(239, 65%, 70%)
CMYK	cmyk(64.8%, 64.2%, 0%, 29.8%)
CIE-LAB	lab(33.94, 35.71, -61.26)
CIE-LCH	lch(33.94, 70.91, 300.24°)
OKLab	oklab(44.51% 0.0187 -0.1766)
OKLCH	oklch(44.51% 0.178 276)
XYZ	xyz(12.0173, 7.9772, 43.5456)
Luminance	0.0798 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Blue With A Hint Of Purple

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#3F40B3 #B3B23F

analogous

#3F7AB3 #3F40B3 #783FB3

triadic

#3F40B3 #B33F40 #40B33F

tetradic

#3F40B3 #B33F7A #B3B23F #3FB378

square

#3F40B3 #B33F7A #B3B23F #3FB378

split-complementary

#3F40B3 #B3783F #7AB33F

monochromatic

#1F2058 #2F3086 #3F40B3 #6667C9 #9394D9

Accessibility & contrast

On white

8.09

#3F40B3 on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

2.60

#3F40B3 on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #3F40B3

8.09:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3F40B3	#FFFFFF	#000000	##FFFFFF
##3F40B3	1.00	8.09	2.60	8.09
#FFFFFF	8.09	1.00	21.00	1.00
#000000	2.60	21.00	1.00	21.00
##FFFFFF	8.09	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#0055B7

Deuteranopia (green-blind)

#004BB1

Tritanopia (blue-blind)

#005D73

Achromatopsia (no color)

#505050

Design tokens & code

CSS

--color: #3f40b3;
/* rgb */ color: rgb(63, 64, 179);
/* oklch */ color: oklch(44.5% 0.178 276.0);

Tailwind

colors: {
  custom: {
    50: '#8275cb',
    500: '#3f40b3',
    950: '#000000',
  },
}

SCSS

$custom: #3f40b3;
$custom-light: #8275cb;
$custom-dark: #000000;

JSON

{
  "hex": "#3f40b3",
  "rgb": {
    "r": 63,
    "g": 64,
    "b": 179
  },
  "hsl": {
    "h": 239.483,
    "s": 47.934,
    "l": 47.451
  },
  "oklch": {
    "l": 0.44513,
    "c": 0.17758,
    "h": 276
  },
  "luminance": 0.07978
}

Semantic roles & 50–950 ramp

primary

#3F40B3

secondary

#C4C489

accent

#D650D8

background

#F8F7FC

surface

#F0EDF9

border

#CBC8D2

text

#0C0813

muted

#7D7B82

Preview Lab

Preview with #3F40B3

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

Preview Lab → · Contrast checker → · Palette generator →