#373739 Color

#373739 is rgb(55, 55, 57) in RGB, hsl(240, 2%, 22%) in HSL, and about cmyk(4%, 4%, 0%, 78%) in CMYK. It has no registered color name of its own — the closest is Onyx (#353839), below the threshold most people can see at ΔE 1.51. White text is the more readable choice on this background.

#373739

HEX#373739

RGBrgb(55, 55, 57)

HSLhsl(240, 2%, 22%)

HSVhsv(240, 4%, 22%)

CMYKcmyk(4%, 4%, 0%, 78%)

OKLCHoklch(33.8% 0.003 286.2)

LABlab(23.12% 0.35 -1.26)

LCHlch(23.12% 1.30 285.49)

What #373739 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 #373739, ordered by CIE76 distance in CIELAB. Anything under about ΔE 2 is a difference most people cannot see.

Onyx#353839ΔE 1.51 Jet#343434ΔE 1.93 Outer Space (Crayola)#2D383AΔE 5 Traffic Black#2A2D2FΔE 5.11 Xumo#413639ΔE 5.35 Gunmetal#2A3439ΔE 5.48

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

#373739 Channel Values

How #373739 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 55 · G 55 · B 57	8-bit channels as sent to the display
HSL	H 240° · S 2% · L 22%	Easiest model for building lighter and darker variants
HSV	H 240° · S 4% · V 22%	Matches the picker in most design tools
CMYK	C 4% · M 4% · Y 0% · K 78%	Approximate ink mix; confirm with an ICC profile before printing
Luminance	11.88:1 vs white · 1.77:1 vs black	WCAG 2.2 relative-luminance contrast ratios

Text Contrast & Accessibility

WCAG 2.2 contrast ratios for text on a #373739 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 text11.88:1AA normal AA large AAA normal

Fails AABlack text1.77:1AA normal AA large AAA normal

Need a specific ratio against another background? Open #373739 in the contrast checker.

Colors That Go With #373739

Pairings derived from color-wheel relationships. The complementary color sits opposite #373739; 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 #373739

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 #373739.

How #373739 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#373739

Protanopia#373739

Protanomaly#373739

Deuteranopia#373739

Deuteranomaly#373739

Tritanopia#373737

Tritanomaly#373738

Achromatopsia#373737

Test a full palette in the color blindness simulator.

Using #373739 in Code

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

CSS custom property--color-373739: #373739;

CSS backgroundbackground-color: #373739;

Tailwind configcolors: { 'color-373739': '#373739' }

SwiftUIColor(red: 0.216, green: 0.216, blue: 0.224)

Android XML<color name="color_373739">#373739</color>

SVG fillfill="#373739"

More Gray Colors

#373739 sits in the gray family. These are its neighbours across that family's full range, each with its own breakdown.

27272a d9d9d9 292524 d8d8d8 292929 d6d6d6 2a2d2f d6d3d1 2b2b2b d4d4d8 2e2e2e d4d4d4 353839 43494e 51484f 5c5c5c 6b6e70 796878 838996 8e8c84 a1a1a1 acacac bebebe d1d1d1

#373739 Frequently Asked Questions

What color is #373739?

#373739 is a dark gray — rgb(55, 55, 57) in RGB and hsl(240, 2%, 22%) in HSL. It carries no registered color name of its own; the closest named color is Onyx (#353839), which is below the threshold most people can see at a CIE76 distance of 1.51.

What is the RGB value of #373739?

#373739 is rgb(55, 55, 57) — red 55, green 55, and blue 57 on the 0-255 scale.

What is the CMYK value of #373739?

#373739 converts to approximately cmyk(4%, 4%, 0%, 78%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.

Should text on #373739 be black or white?

White text is the more readable choice. #373739 scores 11.88:1 against white and 1.77:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.

Can I write #373739 as a CSS color keyword?

No. #373739 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 darkslategray (#2F4F4F) at a CIE76 distance of 15.18, which is visibly different.

Open #373739 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 gray in the color library, the guide to shades of gray, or the full color library.