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green · cool

#40df4e

a balanced, vivid green · cool · closest name: Lime Green

Token name suggestion: Signal Basil

RGB
64, 223, 78
HSL
125°, 71%, 56%
CMYK
71, 0, 65, 13
Luminance
0.5442

#40df4e is a balanced vivid green, 125° on the wheel and 65/100 on the cool side. Put black text on it (11.88:1). As text it scores 1.77:1 on white — use #178921 instead. Nearest name is Lime Green, nearest Tailwind family is green.

hsl(125 71% 56%)rgb(64 223 78)Base step 500AAA inkCool

At a glance

Every number on this page in one read: what #40df4e is made of, how bright it looks, and which way it leans.

Hex
#40df4e
Hue
125°
green
Saturation
71%
vivid
Lightness
56%
balanced
Brightness
87%
HSV value
Perceived
69%
weighted brightness
Luminance
0.5442
WCAG relative
Temperature
Cool
65/100 cool
Color family
Green
Tone
Vivid
Best ink
Black
11.88:1
Closest name
Lime Green
ΔE2000 4.6
Chroma
89.2
LCH, 0–130ish
OKLCH L
0.794
perceptual lightness
Tailwind
green
500 · ΔE 7.9
Web-safe
#33CC66
nearest of 216
Where it sits
Hue125° of 360°
Saturation71%
Lightness56%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #40df4e.

Temperature
Warm ← → Cool65% cool

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

Luminance by channel
Red2%
Green97%
Blue1%

Green carries most of what the eye calls brightness — that is why WCAG weights it 0.7152.

Every format

HEX#40df4e
HEX (8-digit)#40df4eff
RGBrgb(64, 223, 78)
RGBArgba(64, 223, 78, 1)
HSLhsl(125, 71%, 56%)
HSV / HSBhsv(125, 71%, 87%)
HWBhwb(125 25% 13%)
CMYKcmyk(71%, 0%, 65%, 13%)
LABlab(78.7 -68.2 57.4)
LCHlch(78.7 89.2 139.9)
OKLCHoklch(0.794 0.228 144.2)
XYZ (D65)xyz(29.88, 54.41, 16.13)
Decimal4251470
Display P3color(display-p3 0.251 0.875 0.306)
Web-safe#33CC66

Copy-ready code

every platformclick to select
/* CSS */
color: #40df4e;
background-color: #40df4e;
/* CSS custom property */
--brand: #40df4e;
/* Tailwind (arbitrary) */
class="text-[#40df4e] bg-[#40df4e]"
/* SCSS */
$brand: #40df4e;
/* SwiftUI */
Color(red: 0.251, green: 0.875, blue: 0.306)
/* UIKit */
UIColor(red: 0.251, green: 0.875, blue: 0.306, alpha: 1)
/* Android XML */
<color name="brand">#40DF4E</color>
/* Android Compose */
Color(0xFF40DF4E)
/* Flutter */
Color(0xFF40DF4E)
/* Python / OpenCV (BGR) */
(78, 223, 64)
/* Python / PIL (RGB) */
(64, 223, 78)
/* Java AWT */
new Color(64, 223, 78)
/* .NET */
Color.FromArgb(255, 64, 223, 78)
/* OpenGL / Unity (0–1) */
(0.2510f, 0.8745f, 0.3059f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{64,223,78}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #40df4e 85%, white);
border-color: color-mix(in oklab, #40df4e 40%, transparent);
/* theme-aware in one line */
color: light-dark(#126D1A, #D3EED5);
/* relative colour syntax */
--hover: hsl(from #40df4e h s calc(l - 7));

Design tokens

The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.

css custom propertiesclick to select
:root {
  --brand-50: #F3FCF4;
  --brand-100: #E7F8E9;
  --brand-200: #C9F3CD;
  --brand-300: #9FEFA6;
  --brand-400: #6FE779;
  --brand-500: #40df4e;
  --brand-600: #23D233;
  --brand-700: #1DAF2A;
  --brand-800: #178C22;
  --brand-900: #15651C;
  --brand-950: #0D3F12;
  --brand: #40df4e;
  --brand-ink: #000000;
  --brand-surface: #F4FAF5;
  --brand-border: #C0EDC4;
  --brand-hover: #24D734;
  --brand-pressed: #1FB92D;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142415;
    --brand-ink: #D3EED5;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F3FCF4',
        100: '#E7F8E9',
        200: '#C9F3CD',
        300: '#9FEFA6',
        400: '#6FE779',
        500: '#40df4e',
        600: '#23D233',
        700: '#1DAF2A',
        800: '#178C22',
        900: '#15651C',
        950: '#0D3F12',
        DEFAULT: '#40df4e',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F3FCF4,
  '100': #E7F8E9,
  '200': #C9F3CD,
  '300': #9FEFA6,
  '400': #6FE779,
  '500': #40df4e,
  '600': #23D233,
  '700': #1DAF2A,
  '800': #178C22,
  '900': #15651C,
  '950': #0D3F12,
);
$brand-base: #40df4e;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F3FCF4", "$type": "color" },
      "100": { "$value": "#E7F8E9", "$type": "color" },
      "200": { "$value": "#C9F3CD", "$type": "color" },
      "300": { "$value": "#9FEFA6", "$type": "color" },
      "400": { "$value": "#6FE779", "$type": "color" },
      "500": { "$value": "#40df4e", "$type": "color" },
      "600": { "$value": "#23D233", "$type": "color" },
      "700": { "$value": "#1DAF2A", "$type": "color" },
      "800": { "$value": "#178C22", "$type": "color" },
      "900": { "$value": "#15651C", "$type": "color" },
      "950": { "$value": "#0D3F12", "$type": "color" }
    },
    "brandInk": { "$value": "#000000", "$type": "color" }
  }
}

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 #40df4e · 11.88:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.77:1
AA fail · AA large fail · AAA fail
Aa
Black text · 11.88:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #40df4e as text scores 1.77:1 on white and 11.88:1 on black.
Best tinted ink on it, if plain black or white feels flat: #126D1A at 3.68:1.

Make it accessible

A contrast checker tells you that you failed. This tells you what to ship instead — same hue, same saturation, lightness moved only as far as WCAG demands.

The quick fox
#178921 · 4.53:1
AA on white−25% L
#178921
The quick fox
#116619 · 7.15:1
AAA on white−33% L
#116619
The quick fox
#40df4e · 11.88:1
AA on blackalready passes
#40df4e
The quick fox
#40df4e · 11.88:1
AAA on blackalready passes
#40df4e

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #1DAC29 is enough for headings on white. Non-text elements such as icons, chart strokes and focus rings also sit at 3:1 under WCAG 2.2 (1.4.11).

Accessibility — WCAG contrast

Aa
#40df4e on white: 1.77:1
AA ✗ fail · AA-large · AAA
Aa
#40df4e on black: 11.88:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #40df4e as text on that neutral, and that neutral as text on #40df4e.

NeutralRatioBoth directions
White1.77:1AaAa
Slate 501.69:1AaAa
Slate 1001.61:1AaAa
Slate 2001.43:1AaAa
Slate 3001.19:1AaAa
Slate 4001.45:1AaAa
Slate 5002.69:1AaAa
Slate 6004.29:1AaAa
Slate 7005.86:1AaAa
Slate 8008.28:1AaAa
Slate 90010.10:1AaAa
Black11.88:1AaAa
Colour vision deficiency
true color
protanopia · #E3CA3B
deuteranopia · #D1BE5B
tritanopia · #00D9C1

Roughly one man in twelve has some form of colour vision deficiency. If any of the three panels above is hard to tell apart from a neighbouring colour in your palette, add a shape, an icon or a label so the meaning does not rest on hue alone.

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #40df4e is pinned to step 500; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F3FCF4
#E7F8E9
#C9F3CD
#9FEFA6
#6FE779
#40df4e
#23D233
#1DAF2A
#178C22
#15651C
#0D3F12
Base = 500Lightest = 50 · #F3FCF4Darkest = 950 · #0D3F12Text step on white = 900
Perceptual ramp — OKLCH

The same eleven steps expressed in OKLCH, where equal lightness numbers actually look equally spaced. HSL ramps go muddy in the yellows and washed out in the blues; this one does not. Modern browsers render it natively — the hex ramp above is the fallback.

50100200300400500600700800900950
oklch tokensclick to select
:root {
  --brand-50: oklch(0.97 0.057 144.2);
  --brand-100: oklch(0.94 0.091 144.2);
  --brand-200: oklch(0.88 0.137 144.2);
  --brand-300: oklch(0.80 0.177 144.2);
  --brand-400: oklch(0.72 0.209 144.2);
  --brand-500: oklch(0.64 0.228 144.2);
  --brand-600: oklch(0.56 0.228 144.2);
  --brand-700: oklch(0.48 0.214 144.2);
  --brand-800: oklch(0.40 0.191 144.2);
  --brand-900: oklch(0.32 0.159 144.2);
  --brand-950: oklch(0.24 0.125 144.2);
}

Colors that work with #40df4e

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#F4FAF5
Tinted page background
Border#C0EDC4
Hairlines and dividers
Muted text#4B9B52
Captions on the surface
Accent#C83CE3
Second voice, not a rival
Dark variant#126D1A
Hover, pressed, headers
Light variant#E9FBEB
Selected rows, tints
Dark surface#142415
Dark-mode background
Hover#24D734
One step down in lightness
Pressed#1FB92D
Two steps down
Disabled#BBD4BE
Chroma pulled out
Focus ring#47EC56
Offset from the fill so it reads
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

In real components

The same eight roles, wired into the interface patterns you will actually build with them. Every state below is a computed value, not a mock-up.

Buttons and states
Save changesHoverPressedDisabled
OutlineSubtleLinkFocused
Form field
you@company.com

Focus ring uses the light variant so the field still reads as one shape.

Send me product updates
Notice
Your export is ready

The file stays available for seven days. Download it before it expires.

NewBetaDraft
Data
Storage used68%
Acme LtdActive
NorthwindTrial
GlobexActive

How to use #40df4e

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
  • Brand accents, badges and data highlights
  • Chart series and data categories
Use with care
  • Text of any size on white — fails WCAG AA
  • Full-page backgrounds — tiring over long sessions
  • Status meaning — pair it with an icon or label, never colour alone
  • Pairing with a same-lightness hue — edges vibrate
Minimum size as text on white
Not as text
Safe as a fill behind white type
No — use #126D1A
Safe as a 1px border on white
No — use #1DAC29

Meaning and mood

What a colour in this family tends to signal, and how this particular chroma and lightness change the reading.

safegrowingnaturalpermissive

Green means go, well, and grown. It carries finance, sustainability and health with almost no explanation needed.

This is a confident chroma: strong enough to lead a brand, restrained enough to live in an interface all day. The mid lightness keeps it versatile in both themes.

Worth knowing

Red/green pairs are the most common colour-blindness failure — never let the two carry meaning alone.

Reads as
  • FormalityMedium
  • EnergyMedium-high
  • Weight44/100
  • TemperatureCool
  • ApproachabilityBalanced

Colour associations are cultural and vary by market. Treat these as a starting point for a conversation with your audience, not a finding about them.

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#DF40D1
Analogous left#82DF40
Analogous right#40DF9E
Split-complement 1#9E40DF
Split-complement 2#DF4082
Triadic 1#4E40DF
Triadic 2#DF4E40
Tetradic#4082DF
On the wheel
Base+30°−30°+120°+240°+180°125°

#40df4e sits at 125°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red25.1%
Green87.5%
Blue30.6%
R · 0–255
64
0x40
G · 0–255
223
0xdf
B · 0–255
78
0x4e

CMYK percentages

Cyan71.3%
Magenta0.0%
Yellow65.0%
Key (black)12.5%

Total ink coverage is 149%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#40df4e text on a black background

contrast 11.88:1

Card sample

#40df4e text on a white background

contrast 1.77:1

Card sample

#40df4e on grey

1.61:1

#40df4e on its own surface

1.67:1

#40df4e on its dark surface

9.19:1

CSS3 live lab

Text font color

The quick brown fox

color: #40df4e;
Background color
Panel with #40df4e background
background-color: #40df4e;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #40df4e;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(64, 223, 78, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(64, 223, 78, 0.45);
Border & gradient
Gradient panel
border: 3px solid #40df4e;
background: linear-gradient(135deg, #40df4e, #40DFB8);
Gradient text

Gradient headline

background: linear-gradient(90deg, #40df4e, #40DEDF);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #40df4e;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #40df4e;
caret-color: #40df4e;
Left rule
Pull quote or callout
border-left: 4px solid #40df4e;
Ring + tint
Selected chip
background: #E9FBEB;
box-shadow: inset 0 0 0 2px #40df4e;
Conic badge
68%
background: conic-gradient(#40df4e 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #40df4e over white; the bottom row is the same alpha over a checkerboard, so you can see what survives on a photo or a video.

Bottom row of hexes is the flattened result over white — use those when a design tool refuses transparency, or when you need a solid fallback.

alpha in every syntaxclick to select
rgba(64, 223, 78, 0.5)
rgb(64 223 78 / 50%)
#40df4e80
hsl(125 71% 56% / 50%)
color-mix(in srgb, #40df4e 50%, transparent)
Alpha8-digit hexFlat on white
10%#40df4e1a#ECFCED
20%#40df4e33#D9F9DC
40%#40df4e66#B3F2B8
60%#40df4e99#8CEC95
80%#40df4ecc#66E571

Gradients from #40df4e

Six recipes, each built from this hex and shown with the exact CSS that produced it.

Elevation
Same hue, three lightnesses — safe anywhere
background: linear-gradient(135deg, #75E87F, #40df4e 45%, #126D1A);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #40df4e, #26DBBD);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #40df4e, #DF40D1);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #8FEC97 0%, #40df4e 45%, #126D1A 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4FAF5, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #A8E66C 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #5AE3B6 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #126D1A 0%, transparent 65%), #40df4e;

Monochromatic scale

Palettes built from #40df4e

Shades — darker

Tints — lighter

Tones — desaturated

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.

#40df4e 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

Converts to four-color process without much drama. Proof it anyway.

On screens

Holds up across typical panel gamma. Still worth checking on an uncalibrated laptop, where mid-tones shift most.

In dark mode

Usable as-is on a dark surface at 11.88:1.

Explore nearby colors

Small, deliberate steps away from this hex — useful when you are hunting for the version of a colour that finally feels right.

#40df4e, answered

What color is #40df4e?

#40df4e is a balanced vivid green, closest to Lime Green (ΔE2000 4.6). It sits at 125° on the hue wheel with 71% saturation and 56% lightness, which reads as cool.

What is the RGB value of #40df4e?

rgb(64, 223, 78) — 64 red, 223 green and 78 blue out of 255, or 25.1% / 87.5% / 30.6% by channel.

What is #40df4e in HSL and HSV?

hsl(125, 71%, 56%) and hsv(125, 71%, 87%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #40df4e a light or a dark color?

It is a light color. Relative luminance is 0.5442 and perceived brightness is 69%, so black text on it reaches 11.88:1.

Should I use black or white text on #40df4e?

Black. It scores 11.88:1 against #40df4e, versus 1.77:1 for white — AAA at any size.

Is #40df4e accessible on a white background?

#40df4e on white scores 1.77:1, which fails WCAG AA at every size. Darken it to #178921 to reach 4.5:1, or #116619 for 7:1.

What is the complementary color of #40df4e?

#DF40D1 sits directly opposite on the wheel. Softer options are the split-complements #9E40DF and #DF4082, which give the same contrast with far less vibration.

What colors go well with #40df4e?

For interface work: #F4FAF5 as the surface, #C0EDC4 for borders, #4B9B52 for secondary text, #C83CE3 as an accent and #126D1A for hover and pressed states. For a palette, the analogous pair #82DF40 and #40DF9E stays calm, while #DF40D1 is the loudest partner.

What is #40df4e in CMYK for printing?

cmyk(71%, 0%, 65%, 13%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #40df4e warm or cool?

Cool — it scores 65 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #6CDF40; nudged cooler, #3EE188.

Which Tailwind color is closest to #40df4e?

The green family — its 500 step is #22c55e, ΔE2000 7.9 away. That is a visible difference, so define #40df4e as a custom token rather than reaching for the built-in.

How do I use #40df4e in Tailwind CSS?

Inline it as an arbitrary value with bg-[#40df4e] or text-[#40df4e], or register the whole ramp under theme.extend.colors.brand so you get bg-brand-500 and friends. The generated 50–950 scale on this page is ready to paste into your config.

What is #40df4e with 50% opacity?

rgba(64, 223, 78, 0.5), or #40df4e80 in eight-digit hex. Over white that composites to #A0EFA7; over black, #207027.

Is #40df4e a web-safe color?

No. The nearest web-safe colour is #33CC66, ΔE2000 6.7 away. The palette only matters for legacy displays and some email clients now.

What does the color #40df4e mean?

As a green, it reads safe, growing, natural. Green means go, well, and grown. It carries finance, sustainability and health with almost no explanation needed. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #40df4e?

The safest is same-hue elevation: linear-gradient(135deg, #75E87F, #40df4e 45%, #126D1A). For more colour, a short hue run to #26DBBD keeps it rich without turning muddy.

Work with #40df4e in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #40df4e at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.