#B51203 Color

#B51203 is rgb(181, 18, 3) in RGB, hsl(5, 97%, 36%) in HSL, and about cmyk(0%, 90%, 98%, 29%) in CMYK. It has no registered color name of its own — the closest is Mordant Red 19 (#AE0C00), below the threshold most people can see at ΔE 2.19. White text is the more readable choice on this background.

#B51203

HEX#B51203

RGBrgb(181, 18, 3)

HSLhsl(5, 97%, 36%)

HSVhsv(5, 98%, 71%)

CMYKcmyk(0%, 90%, 98%, 29%)

OKLCHoklch(49.1% 0.194 30.2)

LABlab(39.10% 60.38 52.95)

LCHlch(39.10% 80.31 41.25)

What #B51203 Is Called

Most hex codes have no name: there are 16.7 million of them and a few thousand registered names. These are the named colors nearest to #B51203, ordered by CIE76 distance in CIELAB. Anything under about ΔE 2 is a difference most people cannot see.

Mordant Red 19#AE0C00ΔE 2.19 Medium Red#B10304ΔE 2.28 International Orange (Engineering)#BA160CΔE 2.48 Tomato Sauce#B21807ΔE 2.8 Rufous#A81C07ΔE 7.39 Lemon Iced Tea#BD3000ΔE 7.5

Browse the full index of named colors A-Z or every red in the library.

#B51203 Channel Values

How #B51203 breaks down in each color model. Hue is measured in degrees around the color wheel; saturation, lightness, and the CMYK inks are percentages.

Model	Channels	Notes
RGB	R 181 · G 18 · B 3	8-bit channels as sent to the display
HSL	H 5° · S 97% · L 36%	Easiest model for building lighter and darker variants
HSV	H 5° · S 98% · V 71%	Matches the picker in most design tools
CMYK	C 0% · M 90% · Y 98% · K 29%	Approximate ink mix; confirm with an ICC profile before printing
Luminance	6.88:1 vs white · 3.05:1 vs black	WCAG 2.2 relative-luminance contrast ratios

Text Contrast & Accessibility

WCAG 2.2 contrast ratios for text on a #B51203 background. AA requires 4.5:1 for normal text and 3:1 for large text; AAA requires 7:1. Contrast is one check, not a full accessibility review.

TextWhite text6.88:1AA normal AA large AAA normal

Fails AABlack text3.05:1AA normal AA large AAA normal

Need a specific ratio against another background? Open #B51203 in the contrast checker.

Colors That Go With #B51203

Pairings derived from color-wheel relationships. The complementary color sits opposite #B51203; analogous colors sit beside it; triadic and split-complementary sets spread evenly around the wheel. Select any swatch for its own breakdown.

Base

Complementary

Analogous

Analogous

Triadic

Triadic

Split comp.

Split comp.

Tints & Shades of #B51203

Lighter tints and darker shades built by moving the lightness channel while holding hue and saturation, which is what you want for hover states, backgrounds, and text variants.

Tints

Shades

Want a full 50-950 ramp with semantic roles? Generate design tokens from #B51203.

How #B51203 Looks with Color Vision Deficiency

Simulated with the Viénot, Brettel & Mollon LMS projection model. Anomalous types are rendered as partial versions of the matching dichromacy, which is an approximation rather than a per-person clinical model.

Typical#B51203

Protanopia#525200

Protanomaly#854100

Deuteranopia#6E6E00

Deuteranomaly#905800

Tritanopia#B51111

Tritanomaly#B5110C

Achromatopsia#5A5A5A

Test a full palette in the color blindness simulator.

Using #B51203 in Code

Copy-ready declarations for the places this color usually ends up.

CSS custom property--color-b51203: #B51203;

CSS backgroundbackground-color: #B51203;

Tailwind configcolors: { 'color-b51203': '#B51203' }

SwiftUIColor(red: 0.710, green: 0.071, blue: 0.012)

Android XML<color name="color_b51203">#B51203</color>

SVG fillfill="#B51203"

More Red Colors

#B51203 sits in the red family. These are its neighbours across that family's full range, each with its own breakdown.

1f0000 fffafa 1f0005 fff5f5 1f0008 fff1f2 240000 fff1f0 240909 fff0f2 270707 ffedeb 4e0707 710f04 940000 a81c07 c0362c cdacac e30022 ee204d fa8072 ff1818 ff6467 ffb7c5

#B51203 Frequently Asked Questions

What color is #B51203?

#B51203 is a dark red — rgb(181, 18, 3) in RGB and hsl(5, 97%, 36%) in HSL. It carries no registered color name of its own; the closest named color is Mordant Red 19 (#AE0C00), which is below the threshold most people can see at a CIE76 distance of 2.19.

What is the RGB value of #B51203?

#B51203 is rgb(181, 18, 3) — red 181, green 18, and blue 3 on the 0-255 scale.

What is the CMYK value of #B51203?

#B51203 converts to approximately cmyk(0%, 90%, 98%, 29%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.

Should text on #B51203 be black or white?

White text is the more readable choice. #B51203 scores 6.88:1 against white and 3.05:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.

Can I write #B51203 as a CSS color keyword?

No. #B51203 is not one of the CSS color keywords, so it has to be written as a hex, rgb() or hsl() value. The closest keyword is firebrick (#B22222) at a CIE76 distance of 14.3, which is visibly different.

Open #B51203 in a Tool

Hex to RGB Hex to HSL Hex to CMYK Hex to OKLCH Hex to Pantone Build a palette Make a gradient

Keep exploring: every red in the color library, the guide to shades of red, or the full color library.