#3F66CB#3F66CB

#3F66CB is a mid, vivid blue. Relative luminance 0.149; OKLCH L 53.7% C 0.163 H 265.4°. Best body text is #FFFFFF at 5.28:1 contrast (WCAG AA passes).

Color values

HEX	#3F66CB
RGB	rgb(63, 102, 203)
HSL	hsl(223, 57%, 52%)
HSV	hsv(223, 69%, 80%)
CMYK	cmyk(69%, 49.8%, 0%, 20.4%)
CIE-LAB	lab(45.45, 19.97, -56.57)
CIE-LCH	lch(45.45, 59.99, 289.45°)
OKLab	oklab(53.69% -0.0131 -0.1624)
OKLCH	oklch(53.69% 0.163 265.4)
XYZ	xyz(17.5770, 14.8695, 58.4321)
Luminance	0.1487 (WCAG relative)
Temperature	cool
Family	blue

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#3F66CB #CBA43F

analogous

#3FACCB #3F66CB #5E3FCB

triadic

#3F66CB #CB3F66 #66CB3F

tetradic

#3F66CB #CB3FAC #CBA43F #3FCB5E

square

#3F66CB #CB3FAC #CBA43F #3FCB5E

split-complementary

#3F66CB #CB5E3F #ACCB3F

monochromatic

#1F3671 #2C4CA1 #3F66CB #6F8CD8 #9FB3E5

Accessibility & contrast

On white

5.28

#3F66CB on #FFFFFF

AA ✓AA large ✓AAA ✗

On black

3.97

#3F66CB on #000000

AA ✗AA large ✓AAA ✗

Best text color

#FFFFFF on #3F66CB

5.28:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##3F66CB	#FFFFFF	#000000	##FFFFFF
##3F66CB	1.00	5.28	3.97	5.28
#FFFFFF	5.28	1.00	21.00	1.00
#000000	3.97	21.00	1.00	21.00
##FFFFFF	5.28	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#2C72CF

Deuteranopia (green-blind)

#0066C9

Tritanopia (blue-blind)

#007E8F

Achromatopsia (no color)

#6C6C6C

Design tokens & code

CSS

--color: #3f66cb;
/* rgb */ color: rgb(63, 102, 203);
/* oklch */ color: oklch(53.7% 0.163 265.4);

Tailwind

colors: {
  custom: {
    50: '#8491db',
    500: '#3f66cb',
    950: '#000000',
  },
}

SCSS

$custom: #3f66cb;
$custom-light: #8491db;
$custom-dark: #000000;

JSON

{
  "hex": "#3f66cb",
  "rgb": {
    "r": 63,
    "g": 102,
    "b": 203
  },
  "hsl": {
    "h": 223.286,
    "s": 57.377,
    "l": 52.157
  },
  "oklch": {
    "l": 0.53685,
    "c": 0.1629,
    "h": 265.4
  },
  "luminance": 0.14871
}

Semantic roles & 50–950 ramp

primary

#3F66CB

secondary

#D1C094

accent

#B647E1

background

#F8F8FD

surface

#F0F0FB

border

#CBCBD4

text

#0C0C15

muted

#7D7D83

Preview Lab

Preview with #3F66CB

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

Preview Lab → · Contrast checker → · Palette generator →