#66EF39 Color

#66EF39 is rgb(102, 239, 57) in RGB, hsl(105, 85%, 58%) in HSL, and about cmyk(57%, 0%, 76%, 6%) in CMYK. It has no registered color name of its own — the closest is SGBUS Green (#55DD33), clearly related but distinguishable side by side at ΔE 7.42. Black text is the more readable choice on this background.

#66EF39

HEX#66EF39

RGBrgb(102, 239, 57)

HSLhsl(105, 85%, 58%)

HSVhsv(105, 76%, 94%)

CMYKcmyk(57%, 0%, 76%, 6%)

OKLCHoklch(84.3% 0.244 139.4)

LABlab(84.53% -61.58 69.67)

LCHlch(84.53% 92.98 131.47)

What #66EF39 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 #66EF39, ordered by CIE76 distance in CIELAB. Anything under about ΔE 2 is a difference most people cannot see.

SGBUS Green#55DD33ΔE 7.42 Spring Frost#87FF2AΔE 11.59 Screamin' Green#66FF66ΔE 12.33 Lawn Green#7CFC00ΔE 14.12 French Lime#9EFD38ΔE 14.67 Chartreuse#7FFF00ΔE 15.23

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

#66EF39 Channel Values

How #66EF39 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 102 · G 239 · B 57	8-bit channels as sent to the display
HSL	H 105° · S 85% · L 58%	Easiest model for building lighter and darker variants
HSV	H 105° · S 76% · V 94%	Matches the picker in most design tools
CMYK	C 57% · M 0% · Y 76% · K 6%	Approximate ink mix; confirm with an ICC profile before printing
Luminance	1.5:1 vs white · 13.97:1 vs black	WCAG 2.2 relative-luminance contrast ratios

Text Contrast & Accessibility

WCAG 2.2 contrast ratios for text on a #66EF39 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.

Fails AAWhite text1.5:1AA normal AA large AAA normal

TextBlack text13.97:1AA normal AA large AAA normal

Need a specific ratio against another background? Open #66EF39 in the contrast checker.

Colors That Go With #66EF39

Pairings derived from color-wheel relationships. The complementary color sits opposite #66EF39; 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 #66EF39

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 #66EF39.

How #66EF39 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#66EF39

Protanopia#DFDF3B

Protanomaly#BBE63A

Deuteranopia#CFCF46

Deuteranomaly#AFDC41

Tritanopia#86E2E2

Tritanomaly#7AE7B7

Achromatopsia#D3D3D3

Test a full palette in the color blindness simulator.

Using #66EF39 in Code

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

CSS custom property--color-66ef39: #66EF39;

CSS backgroundbackground-color: #66EF39;

Tailwind configcolors: { 'color-66ef39': '#66EF39' }

SwiftUIColor(red: 0.400, green: 0.937, blue: 0.224)

Android XML<color name="color_66ef39">#66EF39</color>

SVG fillfill="#66EF39"

More Green Colors

#66EF39 sits in the green family. These are its neighbours across that family's full range, each with its own breakdown.

000200 fdfff5 001f00 f7fee7 002400 f7fbf5 002c22 f5fffa 002e00 f5fff5 003300 f0fff0 008000 00db87 0d542b 20483f 33cc66 46c399 5ea500 728639 91e0b7 a3f5d8 bcd7bc d1ffed

#66EF39 Frequently Asked Questions

What color is #66EF39?

#66EF39 is a mid-tone green — rgb(102, 239, 57) in RGB and hsl(105, 85%, 58%) in HSL. It carries no registered color name of its own; the closest named color is SGBUS Green (#55DD33), which is clearly related but distinguishable side by side at a CIE76 distance of 7.42.

What is the RGB value of #66EF39?

#66EF39 is rgb(102, 239, 57) — red 102, green 239, and blue 57 on the 0-255 scale.

What is the CMYK value of #66EF39?

#66EF39 converts to approximately cmyk(57%, 0%, 76%, 6%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.

Should text on #66EF39 be black or white?

Black text is the more readable choice. #66EF39 scores 1.5:1 against white and 13.97:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.

Can I write #66EF39 as a CSS color keyword?

No. #66EF39 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 lawngreen (#7CFC00) at a CIE76 distance of 14.12, which is visibly different.

Open #66EF39 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 green in the color library, the guide to shades of green, or the full color library.