#EFFF42 Color

#EFFF42 is rgb(239, 255, 66) in RGB, hsl(65, 100%, 63%) in HSL, and about cmyk(6%, 0%, 74%, 0%) in CMYK. It has no registered color name of its own — the closest is Maximum Yellow (#FAFA37), clearly related but distinguishable side by side at ΔE 7.02. Black text is the more readable choice on this background.

#EFFF42

HEX#EFFF42

RGBrgb(239, 255, 66)

HSLhsl(65, 100%, 63%)

HSVhsv(65, 74%, 100%)

CMYKcmyk(6%, 0%, 74%, 0%)

OKLCHoklch(95.7% 0.198 114.5)

LABlab(96.50% -21.18 81.18)

LCHlch(96.50% 83.89 104.63)

What #EFFF42 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 #EFFF42, ordered by CIE76 distance in CIELAB. Anything under about ΔE 2 is a difference most people cannot see.

Maximum Yellow#FAFA37ΔE 7.02 Dandelion#DDF719ΔE 7.79 Yellow (RYB)#FEFE33ΔE 8.04 Watermelon Yellow#EEFF1BΔE 8.33 Xanthic#EEED09ΔE 10.67 Lemon Lime#E3FF00ΔE 11.2

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

#EFFF42 Channel Values

How #EFFF42 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 239 · G 255 · B 66	8-bit channels as sent to the display
HSL	H 65° · S 100% · L 63%	Easiest model for building lighter and darker variants
HSV	H 65° · S 74% · V 100%	Matches the picker in most design tools
CMYK	C 6% · M 0% · Y 74% · K 0%	Approximate ink mix; confirm with an ICC profile before printing
Luminance	1.1:1 vs white · 19.05:1 vs black	WCAG 2.2 relative-luminance contrast ratios

Text Contrast & Accessibility

WCAG 2.2 contrast ratios for text on a #EFFF42 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 text1.1:1AA normal AA large AAA normal

TextBlack text19.05:1AA normal AA large AAA normal

Need a specific ratio against another background? Open #EFFF42 in the contrast checker.

Colors That Go With #EFFF42

Pairings derived from color-wheel relationships. The complementary color sits opposite #EFFF42; 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 #EFFF42

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 #EFFF42.

How #EFFF42 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#EFFF42

Protanopia#FCFC42

Protanomaly#F7FD42

Deuteranopia#FAFA44

Deuteranomaly#F6FC43

Tritanopia#FDF1F1

Tritanomaly#F8F7C4

Achromatopsia#F4F4F4

Test a full palette in the color blindness simulator.

Using #EFFF42 in Code

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

CSS custom property--color-efff42: #EFFF42;

CSS backgroundbackground-color: #EFFF42;

Tailwind configcolors: { 'color-efff42': '#EFFF42' }

SwiftUIColor(red: 0.937, green: 1.000, blue: 0.259)

Android XML<color name="color_efff42">#EFFF42</color>

SVG fillfill="#EFFF42"

More Green Colors

#EFFF42 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

#EFFF42 Frequently Asked Questions

What color is #EFFF42?

#EFFF42 is a light green — rgb(239, 255, 66) in RGB and hsl(65, 100%, 63%) in HSL. It carries no registered color name of its own; the closest named color is Maximum Yellow (#FAFA37), which is clearly related but distinguishable side by side at a CIE76 distance of 7.02.

What is the RGB value of #EFFF42?

#EFFF42 is rgb(239, 255, 66) — red 239, green 255, and blue 66 on the 0-255 scale.

What is the CMYK value of #EFFF42?

#EFFF42 converts to approximately cmyk(6%, 0%, 74%, 0%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.

Should text on #EFFF42 be black or white?

Black text is the more readable choice. #EFFF42 scores 1.1:1 against white and 19.05:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.

Can I write #EFFF42 as a CSS color keyword?

No. #EFFF42 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 yellow (#FFFF00) at a CIE76 distance of 13.42, which is visibly different.

Open #EFFF42 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.