#3F40BB#3F40BB

#3F40BB is a mid, vivid blue. Relative luminance 0.083; OKLCH L 45.2% C 0.188 H 275.5°. Best body text is #FFFFFF at 7.89:1 contrast (WCAG AA passes).

Color values

HEX	#3F40BB
RGB	rgb(63, 64, 187)
HSL	hsl(240, 50%, 49%)
HSV	hsv(240, 66%, 73%)
CMYK	cmyk(66.3%, 65.8%, 0%, 26.7%)
CIE-LAB	lab(34.62, 38.43, -64.86)
CIE-LCH	lch(34.62, 75.39, 300.64°)
OKLab	oklab(45.22% 0.018 -0.1872)
OKLCH	oklch(45.22% 0.188 275.5)
XYZ	xyz(12.8500, 8.3103, 47.9309)
Luminance	0.0831 (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

#3F40BB #BBBA3F

analogous

#3F7EBB #3F40BB #7C3FBB

triadic

#3F40BB #BB3F40 #40BB3F

tetradic

#3F40BB #BB3F7E #BBBA3F #3FBB7C

square

#3F40BB #BB3F7E #BBBA3F #3FBB7C

split-complementary

#3F40BB #BB7C3F #7EBB3F

monochromatic

#20215F #30308D #3F40BB #6A6BCD #9899DC

Accessibility & contrast

On white

7.89

#3F40BB on #FFFFFF

AA ✓AA large ✓AAA ✓

On black

2.66

#3F40BB on #000000

AA ✗AA large ✗AAA ✗

Best text color

#FFFFFF on #3F40BB

7.89:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3F40BB	#FFFFFF	#000000	##FFFFFF
##3F40BB	1.00	7.89	2.66	7.89
#FFFFFF	7.89	1.00	21.00	1.00
#000000	2.66	21.00	1.00	21.00
##FFFFFF	7.89	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#0057BF

Deuteranopia (green-blind)

#004CB9

Tritanopia (blue-blind)

#006078

Achromatopsia (no color)

#515151

Design tokens & code

CSS

--color: #3f40bb;
/* rgb */ color: rgb(63, 64, 187);
/* oklch */ color: oklch(45.2% 0.188 275.5);

Tailwind

colors: {
  custom: {
    50: '#8375d0',
    500: '#3f40bb',
    950: '#000000',
  },
}

SCSS

$custom: #3f40bb;
$custom-light: #8375d0;
$custom-dark: #000000;

JSON

{
  "hex": "#3f40bb",
  "rgb": {
    "r": 63,
    "g": 64,
    "b": 187
  },
  "hsl": {
    "h": 239.516,
    "s": 49.6,
    "l": 49.02
  },
  "oklch": {
    "l": 0.45224,
    "c": 0.18803,
    "h": 275.5
  },
  "luminance": 0.08311
}

Semantic roles & 50–950 ramp

primary

#3F40BB

secondary

#C8C88E

accent

#D84FD9

background

#F8F7FC

surface

#F0EDF9

border

#CBC8D2

text

#0C0814

muted

#7D7B82

Preview Lab

Preview with #3F40BB

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

Preview Lab → · Contrast checker → · Palette generator →