#B31B1B#B31B1B

#B31B1B is a mid, vivid red. Relative luminance 0.104; OKLCH L 49.3% C 0.186 H 27.5°. Best body text is #FFFFFF at 6.80:1 contrast (WCAG AA passes).

Color values

HEX	#B31B1B
RGB	rgb(179, 27, 27)
HSL	hsl(0, 74%, 40%)
HSV	hsv(0, 85%, 70%)
CMYK	cmyk(0%, 84.9%, 84.9%, 29.8%)
CIE-LAB	lab(38.64, 57.78, 41.05)
CIE-LCH	lch(38.64, 70.88, 35.39°)
OKLab	oklab(49.34% 0.1647 0.0857)
OKLCH	oklch(49.34% 0.186 27.5)
XYZ	xyz(19.1826, 10.4499, 2.0437)
Luminance	0.1045 (WCAG relative)
Temperature	warm
Family	red

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#B31B1B #1BB3B3

analogous

#B31B67 #B31B1B #B3671B

triadic

#B31B1B #1BB31B #1B1BB3

tetradic

#B31B1B #67B31B #1BB3B3 #671BB3

square

#B31B1B #67B31B #1BB3B3 #671BB3

split-complementary

#B31B1B #1BB367 #1B67B3

monochromatic

#490B0B #7E1313 #B31B1B #DF2C2C #E76161

Accessibility & contrast

On white

6.80

#B31B1B on #FFFFFF

AA ✓AA large ✓AAA ✗

On black

3.09

#B31B1B on #000000

AA ✗AA large ✓AAA ✗

Best text color

#FFFFFF on #B31B1B

6.80:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##B31B1B	#FFFFFF	#000000	##FFFFFF
##B31B1B	1.00	6.80	3.09	6.80
#FFFFFF	6.80	1.00	21.00	1.00
#000000	3.09	21.00	1.00	21.00
##FFFFFF	6.80	1.00	21.00	1.00

Color blindness preview

Protanopia (red-blind)

#4F4618

Deuteranopia (green-blind)

#736611

Tritanopia (blue-blind)

#C6001E

Achromatopsia (no color)

#5B5B5B

Design tokens & code

CSS

--color: #b31b1b;
/* rgb */ color: rgb(179, 27, 27);
/* oklch */ color: oklch(49.3% 0.186 27.5);

Tailwind

colors: {
  custom: {
    50: '#d46a59',
    500: '#b31b1b',
    950: '#000000',
  },
}

SCSS

$custom: #b31b1b;
$custom-light: #d46a59;
$custom-dark: #000000;

JSON

{
  "hex": "#b31b1b",
  "rgb": {
    "r": 179,
    "g": 27,
    "b": 27
  },
  "hsl": {
    "h": 0,
    "s": 73.786,
    "l": 40.392
  },
  "oklch": {
    "l": 0.49337,
    "c": 0.18571,
    "h": 27.5
  },
  "luminance": 0.10447
}

Semantic roles & 50–950 ramp

primary

#B31B1B

secondary

#5ECCCC

accent

#F0F037

background

#FEF6F5

surface

#FDECE9

border

#D5C7C5

text

#160703

muted

#847A78

Preview Lab

Preview with #B31B1B

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

Preview Lab → · Contrast checker → · Palette generator →