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green · cool

#40df88

a balanced, vivid green · cool · closest name: Medium Spring Green

Token name suggestion: True Basil

RGB
64, 223, 136
HSL
147°, 71%, 56%
CMYK
71, 0, 39, 13
Luminance
0.5564

#40df88 is a balanced vivid green, 147° on the wheel and 74/100 on the cool side. Put black text on it (12.13:1). As text it scores 1.73:1 on white — use #168448 instead. Nearest name is Medium Spring Green, nearest Tailwind family is green.

hsl(147 71% 56%)rgb(64 223 136)Base step 500AAA inkCool

At a glance

Every number on this page in one read: what #40df88 is made of, how bright it looks, and which way it leans.

Hex
#40df88
Hue
147°
green
Saturation
71%
vivid
Lightness
56%
balanced
Brightness
87%
HSV value
Perceived
71%
weighted brightness
Luminance
0.5564
WCAG relative
Temperature
Cool
74/100 cool
Color family
Green
Tone
Vivid
Best ink
Black
12.13:1
Closest name
Medium Spring Green
ΔE2000 6
Chroma
67.6
LCH, 0–130ish
OKLCH L
0.802
perceptual lightness
Tailwind
green
500 · ΔE 7.5
Web-safe
#33CC99
nearest of 216
Where it sits
Hue147° 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 #40df88.

Temperature
Warm ← → Cool74% 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%
Green95%
Blue3%

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

Every format

HEX#40df88
HEX (8-digit)#40df88ff
RGBrgb(64, 223, 136)
RGBArgba(64, 223, 136, 1)
HSLhsl(147, 71%, 56%)
HSV / HSBhsv(147, 71%, 87%)
HWBhwb(147 25% 13%)
CMYKcmyk(71%, 0%, 39%, 13%)
LABlab(79.4 -60.0 31.1)
LCHlch(79.4 67.6 152.6)
OKLCHoklch(0.802 0.180 154.4)
XYZ (D65)xyz(32.94, 55.64, 32.29)
Decimal4251528
Display P3color(display-p3 0.251 0.875 0.533)
Web-safe#33CC99

Copy-ready code

every platformclick to select
/* CSS */
color: #40df88;
background-color: #40df88;
/* CSS custom property */
--brand: #40df88;
/* Tailwind (arbitrary) */
class="text-[#40df88] bg-[#40df88]"
/* SCSS */
$brand: #40df88;
/* SwiftUI */
Color(red: 0.251, green: 0.875, blue: 0.533)
/* UIKit */
UIColor(red: 0.251, green: 0.875, blue: 0.533, alpha: 1)
/* Android XML */
<color name="brand">#40DF88</color>
/* Android Compose */
Color(0xFF40DF88)
/* Flutter */
Color(0xFF40DF88)
/* Python / OpenCV (BGR) */
(136, 223, 64)
/* Python / PIL (RGB) */
(64, 223, 136)
/* Java AWT */
new Color(64, 223, 136)
/* .NET */
Color.FromArgb(255, 64, 223, 136)
/* OpenGL / Unity (0–1) */
(0.2510f, 0.8745f, 0.5333f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{64,223,136}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #40df88 85%, white);
border-color: color-mix(in oklab, #40df88 40%, transparent);
/* theme-aware in one line */
color: light-dark(#126D3C, #D3EEDF);
/* relative colour syntax */
--hover: hsl(from #40df88 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: #F3FCF7;
  --brand-100: #E7F8EF;
  --brand-200: #C9F3DC;
  --brand-300: #9FEFC3;
  --brand-400: #6FE7A5;
  --brand-500: #40df88;
  --brand-600: #23D272;
  --brand-700: #1DAF5F;
  --brand-800: #178C4C;
  --brand-900: #156539;
  --brand-950: #0D3F24;
  --brand: #40df88;
  --brand-ink: #000000;
  --brand-surface: #F4FAF7;
  --brand-border: #C0EDD4;
  --brand-hover: #24D775;
  --brand-pressed: #1FB965;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #14241B;
    --brand-ink: #D3EEDF;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F3FCF7',
        100: '#E7F8EF',
        200: '#C9F3DC',
        300: '#9FEFC3',
        400: '#6FE7A5',
        500: '#40df88',
        600: '#23D272',
        700: '#1DAF5F',
        800: '#178C4C',
        900: '#156539',
        950: '#0D3F24',
        DEFAULT: '#40df88',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F3FCF7,
  '100': #E7F8EF,
  '200': #C9F3DC,
  '300': #9FEFC3,
  '400': #6FE7A5,
  '500': #40df88,
  '600': #23D272,
  '700': #1DAF5F,
  '800': #178C4C,
  '900': #156539,
  '950': #0D3F24,
);
$brand-base: #40df88;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F3FCF7", "$type": "color" },
      "100": { "$value": "#E7F8EF", "$type": "color" },
      "200": { "$value": "#C9F3DC", "$type": "color" },
      "300": { "$value": "#9FEFC3", "$type": "color" },
      "400": { "$value": "#6FE7A5", "$type": "color" },
      "500": { "$value": "#40df88", "$type": "color" },
      "600": { "$value": "#23D272", "$type": "color" },
      "700": { "$value": "#1DAF5F", "$type": "color" },
      "800": { "$value": "#178C4C", "$type": "color" },
      "900": { "$value": "#156539", "$type": "color" },
      "950": { "$value": "#0D3F24", "$type": "color" }
    },
    "brandInk": { "$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 #40df88 · 12.13:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.73:1
AA fail · AA large fail · AAA fail
Aa
Black text · 12.13:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #40df88 as text scores 1.73:1 on white and 12.13:1 on black.
Best tinted ink on it, if plain black or white feels flat: #126D3C at 3.70:1.

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
#168448 · 4.74:1
AA on white−26% L
#168448
The quick fox
#116637 · 7.05:1
AAA on white−33% L
#116637
The quick fox
#40df88 · 12.13:1
AA on blackalready passes
#40df88
The quick fox
#40df88 · 12.13:1
AAA on blackalready passes
#40df88

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #1CA75B 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
#40df88 on white: 1.73:1
AA ✗ fail · AA-large · AAA
Aa
#40df88 on black: 12.13:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #40df88 as text on that neutral, and that neutral as text on #40df88.

NeutralRatioBoth directions
White1.73:1AaAa
Slate 501.65:1AaAa
Slate 1001.58:1AaAa
Slate 2001.40:1AaAa
Slate 3001.17:1AaAa
Slate 4001.48:1AaAa
Slate 5002.75:1AaAa
Slate 6004.38:1AaAa
Slate 7005.98:1AaAa
Slate 8008.45:1AaAa
Slate 90010.31:1AaAa
Black12.13:1AaAa
Colour vision deficiency
true color
protanopia · #DECD82
deuteranopia · #CBBF8E
tritanopia · #00DCC9

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. #40df88 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.

#F3FCF7
#E7F8EF
#C9F3DC
#9FEFC3
#6FE7A5
#40df88
#23D272
#1DAF5F
#178C4C
#156539
#0D3F24
Base = 500Lightest = 50 · #F3FCF7Darkest = 950 · #0D3F24Text 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 0.045 154.4);
  --brand-100: oklch(0.94 0.072 154.4);
  --brand-200: oklch(0.88 0.108 154.4);
  --brand-300: oklch(0.80 0.140 154.4);
  --brand-400: oklch(0.72 0.165 154.4);
  --brand-500: oklch(0.64 0.180 154.4);
  --brand-600: oklch(0.56 0.180 154.4);
  --brand-700: oklch(0.48 0.169 154.4);
  --brand-800: oklch(0.40 0.151 154.4);
  --brand-900: oklch(0.32 0.126 154.4);
  --brand-950: oklch(0.24 0.099 154.4);
}

Colors that work with #40df88

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#F4FAF7
Tinted page background
Border#C0EDD4
Hairlines and dividers
Muted text#4B9B6F
Captions on the surface
Accent#E33CC1
Second voice, not a rival
Dark variant#126D3C
Hover, pressed, headers
Light variant#E9FBF1
Selected rows, tints
Dark surface#14241B
Dark-mode background
Hover#24D775
One step down in lightness
Pressed#1FB965
Two steps down
Disabled#BBD4C7
Chroma pulled out
Focus ring#47EC92
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 #40df88

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 #126D3C
Safe as a 1px border on white
No — use #1CA75B

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
  • ApproachabilityReserved

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#DF4097
Analogous left#48DF40
Analogous right#40DFD8
Split-complement 1#D840DF
Split-complement 2#DF4048
Triadic 1#8840DF
Triadic 2#DF8840
Tetradic#4048DF
On the wheel
Base+30°−30°+120°+240°+180°147°

#40df88 sits at 147°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red25.1%
Green87.5%
Blue53.3%
R · 0–255
64
0x40
G · 0–255
223
0xdf
B · 0–255
136
0x88

CMYK percentages

Cyan71.3%
Magenta0.0%
Yellow39.0%
Key (black)12.5%

Total ink coverage is 123%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#40df88 text on a black background

contrast 12.13:1

Card sample

#40df88 text on a white background

contrast 1.73:1

Card sample

#40df88 on grey

1.58:1

#40df88 on its own surface

1.64:1

#40df88 on its dark surface

9.34:1

CSS3 live lab

Text font color

The quick brown fox

color: #40df88;
Background color
Panel with #40df88 background
background-color: #40df88;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #40df88;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(64, 223, 136, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(64, 223, 136, 0.45);
Border & gradient
Gradient panel
border: 3px solid #40df88;
background: linear-gradient(135deg, #40df88, #40CCDF);
Gradient text

Gradient headline

background: linear-gradient(90deg, #40df88, #40A4DF);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #40df88;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #40df88;
caret-color: #40df88;
Left rule
Pull quote or callout
border-left: 4px solid #40df88;
Ring + tint
Selected chip
background: #E9FBF1;
box-shadow: inset 0 0 0 2px #40df88;
Conic badge
68%
background: conic-gradient(#40df88 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #40df88 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, 136, 0.5)
rgb(64 223 136 / 50%)
#40df8880
hsl(147 71% 56% / 50%)
color-mix(in srgb, #40df88 50%, transparent)
Alpha8-digit hexFlat on white
10%#40df881a#ECFCF3
20%#40df8833#D9F9E7
40%#40df8866#B3F2CF
60%#40df8899#8CECB8
80%#40df88cc#66E5A0

Gradients from #40df88

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, #75E8A9, #40df88 45%, #126D3C);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #40df88, #26B6DB);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #40df88, #DF4097);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #8FECB9 0%, #40df88 45%, #126D3C 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4FAF7, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #7CE66C 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #5ADEE3 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #126D3C 0%, transparent 65%), #40df88;

Monochromatic scale

Palettes built from #40df88

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.

#40df88 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 12.13:1.

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.

#40df88, answered

What color is #40df88?

#40df88 is a balanced vivid green, closest to Medium Spring Green (ΔE2000 6). It sits at 147° on the hue wheel with 71% saturation and 56% lightness, which reads as cool.

What is the RGB value of #40df88?

rgb(64, 223, 136) — 64 red, 223 green and 136 blue out of 255, or 25.1% / 87.5% / 53.3% by channel.

What is #40df88 in HSL and HSV?

hsl(147, 71%, 56%) and hsv(147, 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 #40df88 a light or a dark color?

It is a light color. Relative luminance is 0.5564 and perceived brightness is 71%, so black text on it reaches 12.13:1.

Should I use black or white text on #40df88?

Black. It scores 12.13:1 against #40df88, versus 1.73:1 for white — AAA at any size.

Is #40df88 accessible on a white background?

#40df88 on white scores 1.73:1, which fails WCAG AA at every size. Darken it to #168448 to reach 4.5:1, or #116637 for 7:1.

What is the complementary color of #40df88?

#DF4097 sits directly opposite on the wheel. Softer options are the split-complements #D840DF and #DF4048, which give the same contrast with far less vibration.

What colors go well with #40df88?

For interface work: #F4FAF7 as the surface, #C0EDD4 for borders, #4B9B6F for secondary text, #E33CC1 as an accent and #126D3C for hover and pressed states. For a palette, the analogous pair #48DF40 and #40DFD8 stays calm, while #DF4097 is the loudest partner.

What is #40df88 in CMYK for printing?

cmyk(71%, 0%, 39%, 13%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #40df88 warm or cool?

Cool — it scores 74 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #40DF4E; nudged cooler, #3EE1C4.

Which Tailwind color is closest to #40df88?

The green family — its 500 step is #22c55e, ΔE2000 7.5 away. That is a visible difference, so define #40df88 as a custom token rather than reaching for the built-in.

How do I use #40df88 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#40df88] or text-[#40df88], 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 #40df88 with 50% opacity?

rgba(64, 223, 136, 0.5), or #40df8880 in eight-digit hex. Over white that composites to #A0EFC4; over black, #207044.

Is #40df88 a web-safe color?

No. The nearest web-safe colour is #33CC99, ΔE2000 8 away. The palette only matters for legacy displays and some email clients now.

What does the color #40df88 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 #40df88?

The safest is same-hue elevation: linear-gradient(135deg, #75E8A9, #40df88 45%, #126D3C). For more colour, a short hue run to #26B6DB keeps it rich without turning muddy.

Work with #40df88 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #40df88 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.