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#51cf13

a dark, electric green · neutral · closest name: Lime Green

RGB
81, 207, 19
HSL
100°, 83%, 44%
CMYK
61, 0, 91, 19
Luminance
0.4642

At a glance

Every number on this page in one read: what #51cf13 is made of, how bright it looks, and which way it leans.

Hex
#51cf13
Hue
100°
green
Saturation
83%
electric
Lightness
44%
dark
Brightness
81%
HSV value
Perceived
65%
weighted brightness
Luminance
0.4642
WCAG relative
Temperature
Neutral
54/100 cool
Color family
Green
Tone
Electric
Best ink
Black
10.28:1
Closest name
Lime Green
ΔE2000 3.3
Where it sits
Hue100° of 360°
Saturation83%
Lightness44%
Temperature
Warm ← → Cool54% cool

Reads neutral. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.

Every format

HEX#51cf13
RGBrgb(81, 207, 19)
HSLhsl(100, 83%, 44%)
CMYKcmyk(61%, 0%, 91%, 19%)
LABlab(73.8 -63.3 70.3)
LCHlch(73.8 94.6 132.0)
OKLCHoklch(0.753 0.232 138.9)
Decimal5361427
Display P3color(display-p3 0.318 0.812 0.075)

Copy-ready code

/* CSS */
color: #51cf13;
background-color: #51cf13;
/* Tailwind (arbitrary) */
class="text-[#51cf13] bg-[#51cf13]"
/* SCSS */
$brand: #51cf13;
/* SwiftUI */
Color(red: 0.318, green: 0.812, blue: 0.075)
/* Android */
Color.parseColor("#51cf13")
/* Flutter */
Color(0xFF51CF13)
/* Python / OpenCV (BGR) */
(19, 207, 81)

Best text color

Only one of black and white can be right. This is the one, with the number that proves it.

Readable at a glance#000000 on #51cf13 · 10.28:1
Use #000000AAA at every size.
Aa
White text · 2.04:1
AA fail · AA large fail · AAA fail
Aa
Black text · 10.28:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #51cf13 as text scores 2.04:1 on white and 10.28:1 on black.

Accessibility — WCAG contrast

Aa
#51cf13 on white: 2.04:1
AA ✗ fail · AA-large · AAA
Aa
#51cf13 on black: 10.28:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #D5BC00
deuteranopia · #C6B232
tritanopia · #42C8B0

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #51cf13 is pinned to step 600; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F6FCF2
#ECFAE6
#D6F6C6
#B7F698
#93F165
#6FEC31
#51cf13
#49BB11
#3B950E
#2D6C0E
#1C4409
Base = 600Lightest = 50 · #F6FCF2Darkest = 950 · #1C4409
:root {
  --brand-50: #F6FCF2;
  --brand-100: #ECFAE6;
  --brand-200: #D6F6C6;
  --brand-300: #B7F698;
  --brand-400: #93F165;
  --brand-500: #6FEC31;
  --brand-600: #51cf13;
  --brand-700: #49BB11;
  --brand-800: #3B950E;
  --brand-900: #2D6C0E;
  --brand-950: #1C4409;
  --brand: #51cf13;
  --brand-ink: #000000;
}

Colors that work with #51cf13

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#000000
Black wins here
Surface#F6FAF4
Tinted page background
Border#CFEDC0
Hairlines and dividers
Muted text#659B4B
Captions on the surface
Accent#610ED3
Second voice, not a rival
Dark variant#2E750B
Hover, pressed, headers
Light variant#EFFDE8
Selected rows, tints
Dark surface#192414
Dark-mode background
Light mode
Everything in its place

Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.

Primary actionSecondaryBadge
Dark mode
Same hue, inverted

Lightness flips, hue holds. The accent stays the anchor in both themes.

Primary actionSecondaryAccent

How to use #51cf13

Derived from its contrast, chroma and lightness — not from taste.

Works well for
  • Text and icons on dark surfaces
  • Primary buttons and calls to action
  • Focus rings, active and selected states
  • Headers, footers and dark-mode surfaces
  • Brand accents, badges and data highlights
Use with care
  • Text of any size on white — fails WCAG AA
  • Full-page backgrounds — tiring over long sessions
  • Black text placed on it
  • Pairing with a same-lightness hue — edges vibrate

Similar colors

One move away from this hex in each direction. Every swatch is its own page.

Color relationships

The wheel positions with their names attached, so you can grab the one you actually need.

Complementary#9113CF
Analogous left#AFCF13
Analogous right#13CF33
Split-complement 1#3313CF
Split-complement 2#CF13AF
Triadic 1#1351CF
Triadic 2#CF1351
Tetradic#13AFCF

RGB percentages

Red31.8%
Green81.2%
Blue7.5%

CMYK percentages

Cyan60.9%
Magenta0.0%
Yellow90.8%
Key (black)18.8%

Color previews

#51cf13 text on a black background

contrast 10.28:1

Card sample

#51cf13 text on a white background

contrast 2.04:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #51cf13;
Background color
Panel with #51cf13 background
background-color: #51cf13;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #51cf13;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(81, 207, 19, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(81, 207, 19, 0.45);
Border & gradient
Gradient panel
border: 3px solid #51cf13;
background: linear-gradient(135deg, #51cf13, #13CF52);

Monochromatic scale

Palettes built from #51cf13

Shades — darker

Tints — lighter

Color harmonies

Nearest named colors

Ranked with CIEDE2000 across all 139 CSS keywords. Under ΔE 2 the eye stops telling them apart; over ΔE 10 they are plainly different colors.

#51cf13 in the real world

Where a color in this family tends to land, and the interface roles it is usually asked to play.

Industries
SustainabilityFinanceHealth and wellnessAgriculture
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.

#51cf13, answered

What color is #51cf13?

#51cf13 is a dark electric green, closest to Lime Green (ΔE2000 3.3). It sits at 100° on the hue wheel with 83% saturation and 44% lightness, which reads as neutral.

What is the RGB value of #51cf13?

rgb(81, 207, 19) — 81 red, 207 green and 19 blue out of 255, or 31.8% / 81.2% / 7.5% by channel.

Is #51cf13 a light or a dark color?

It is a mid-tone. Relative luminance is 0.4642 and perceived brightness is 65%, so black text on it reaches 10.28:1.

Should I use black or white text on #51cf13?

Black. It scores 10.28:1 against #51cf13, versus 2.04:1 for white — AAA at any size.

What is the complementary color of #51cf13?

#9113CF sits directly opposite on the wheel. Softer options are the split-complements #3313CF and #CF13AF, which give the same contrast with far less vibration.

What colors go well with #51cf13?

For interface work: #F6FAF4 as the surface, #CFEDC0 for borders, #659B4B for secondary text, #610ED3 as an accent and #2E750B for hover and pressed states. For a palette, the analogous pair #AFCF13 and #13CF33 stays calm, while #9113CF is the loudest partner.

What is #51cf13 in CMYK for printing?

cmyk(61%, 0%, 91%, 19%). This is a screen-to-ink approximation — a color this saturated sits outside most CMYK gamuts and will print duller than it looks here.

Is #51cf13 warm or cool?

Neutral — it scores 54 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #96CF13; nudged cooler, #11D118.

Work with #51cf13 in the Color Lab