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green · cool

#40fbab

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

Token name suggestion: Atlas Basil

RGB
64, 251, 171
HSL
154°, 96%, 62%
CMYK
75, 0, 32, 2
Luminance
0.7302

#40fbab is a balanced electric green, 154° on the wheel and 77/100 on the cool side. Put black text on it (15.60:1). As text it scores 1.35:1 on white — use #03864E instead. Nearest name is Medium Spring Green, nearest Tailwind family is green.

hsl(154 96% 62%)rgb(64 251 171)Base step 400AAA inkCool

At a glance

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

Hex
#40fbab
Hue
154°
green
Saturation
96%
electric
Lightness
62%
balanced
Brightness
98%
HSV value
Perceived
80%
weighted brightness
Luminance
0.7302
WCAG relative
Temperature
Cool
77/100 cool
Color family
Green
Tone
Electric
Best ink
Black
15.60:1
Closest name
Medium Spring Green
ΔE2000 2.7
Chroma
68.5
LCH, 0–130ish
OKLCH L
0.878
perceptual lightness
Tailwind
green
500 · ΔE 14
Web-safe
#33FF99
nearest of 216
Where it sits
Hue154° of 360°
Saturation96%
Lightness62%
Saturation × lightness field

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

Temperature
Warm ← → Cool77% 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
Red1%
Green94%
Blue4%

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

Every format

HEX#40fbab
HEX (8-digit)#40fbabff
RGBrgb(64, 251, 171)
RGBArgba(64, 251, 171, 1)
HSLhsl(154, 96%, 62%)
HSV / HSBhsv(154, 75%, 98%)
HWBhwb(154 25% 2%)
CMYKcmyk(75%, 0%, 32%, 2%)
LABlab(88.5 -63.6 25.5)
LCHlch(88.5 68.5 158.2)
OKLCHoklch(0.878 0.184 159.5)
XYZ (D65)xyz(43.96, 73.02, 50.30)
Decimal4258731
Display P3color(display-p3 0.251 0.984 0.671)
Web-safe#33FF99

Copy-ready code

every platformclick to select
/* CSS */
color: #40fbab;
background-color: #40fbab;
/* CSS custom property */
--brand: #40fbab;
/* Tailwind (arbitrary) */
class="text-[#40fbab] bg-[#40fbab]"
/* SCSS */
$brand: #40fbab;
/* SwiftUI */
Color(red: 0.251, green: 0.984, blue: 0.671)
/* UIKit */
UIColor(red: 0.251, green: 0.984, blue: 0.671, alpha: 1)
/* Android XML */
<color name="brand">#40FBAB</color>
/* Android Compose */
Color(0xFF40FBAB)
/* Flutter */
Color(0xFF40FBAB)
/* Python / OpenCV (BGR) */
(171, 251, 64)
/* Python / PIL (RGB) */
(64, 251, 171)
/* Java AWT */
new Color(64, 251, 171)
/* .NET */
Color.FromArgb(255, 64, 251, 171)
/* OpenGL / Unity (0–1) */
(0.2510f, 0.9843f, 0.6706f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{64,251,171}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #40fbab 85%, white);
border-color: color-mix(in oklab, #40fbab 40%, transparent);
/* theme-aware in one line */
color: light-dark(#037D49, #D3EEE2);
/* relative colour syntax */
--hover: hsl(from #40fbab 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: #F1FDF8;
  --brand-100: #E4FCF1;
  --brand-200: #C1FAE2;
  --brand-300: #91FDCF;
  --brand-400: #40fbab;
  --brand-500: #23FA9E;
  --brand-600: #05F08B;
  --brand-700: #04C874;
  --brand-800: #03A05D;
  --brand-900: #077345;
  --brand-950: #05482B;
  --brand: #40fbab;
  --brand-ink: #000000;
  --brand-surface: #F4FAF8;
  --brand-border: #C0EDD9;
  --brand-hover: #1DFA9C;
  --brand-pressed: #05EF8B;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #14241D;
    --brand-ink: #D3EEE2;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F1FDF8',
        100: '#E4FCF1',
        200: '#C1FAE2',
        300: '#91FDCF',
        400: '#40fbab',
        500: '#23FA9E',
        600: '#05F08B',
        700: '#04C874',
        800: '#03A05D',
        900: '#077345',
        950: '#05482B',
        DEFAULT: '#40fbab',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F1FDF8,
  '100': #E4FCF1,
  '200': #C1FAE2,
  '300': #91FDCF,
  '400': #40fbab,
  '500': #23FA9E,
  '600': #05F08B,
  '700': #04C874,
  '800': #03A05D,
  '900': #077345,
  '950': #05482B,
);
$brand-base: #40fbab;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F1FDF8", "$type": "color" },
      "100": { "$value": "#E4FCF1", "$type": "color" },
      "200": { "$value": "#C1FAE2", "$type": "color" },
      "300": { "$value": "#91FDCF", "$type": "color" },
      "400": { "$value": "#40fbab", "$type": "color" },
      "500": { "$value": "#23FA9E", "$type": "color" },
      "600": { "$value": "#05F08B", "$type": "color" },
      "700": { "$value": "#04C874", "$type": "color" },
      "800": { "$value": "#03A05D", "$type": "color" },
      "900": { "$value": "#077345", "$type": "color" },
      "950": { "$value": "#05482B", "$type": "color" }
    },
    "brandInk": { "$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 #40fbab · 15.60:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.35:1
AA fail · AA large fail · AAA fail
Aa
Black text · 15.60:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #40fbab as text scores 1.35:1 on white and 15.60:1 on black.
Best tinted ink on it, if plain black or white feels flat: #037D49 at 3.87:1.

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
#03864E · 4.64:1
AA on white−35% L
#03864E
The quick fox
#026339 · 7.38:1
AAA on white−42% L
#026339
The quick fox
#40fbab · 15.60:1
AA on blackalready passes
#40fbab
The quick fox
#40fbab · 15.60:1
AAA on blackalready passes
#40fbab

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #04A962 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
#40fbab on white: 1.35:1
AA ✗ fail · AA-large · AAA
Aa
#40fbab on black: 15.60:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

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

NeutralRatioBoth directions
White1.35:1AaAa
Slate 501.29:1AaAa
Slate 1001.23:1AaAa
Slate 2001.09:1AaAa
Slate 3001.10:1AaAa
Slate 4001.91:1AaAa
Slate 5003.54:1AaAa
Slate 6005.63:1AaAa
Slate 7007.69:1AaAa
Slate 80010.87:1AaAa
Slate 90013.27:1AaAa
Black15.60:1AaAa
Colour vision deficiency
true color
protanopia · #F8E8A6
deuteranopia · #E1D7B0
tritanopia · #00FAE6

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. #40fbab is pinned to step 400; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F1FDF8
#E4FCF1
#C1FAE2
#91FDCF
#40fbab
#23FA9E
#05F08B
#04C874
#03A05D
#077345
#05482B
Base = 400Lightest = 50 · #F1FDF8Darkest = 950 · #05482BText 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 0.046 159.5);
  --brand-100: oklch(0.94 0.074 159.5);
  --brand-200: oklch(0.88 0.111 159.5);
  --brand-300: oklch(0.80 0.144 159.5);
  --brand-400: oklch(0.72 0.170 159.5);
  --brand-500: oklch(0.64 0.184 159.5);
  --brand-600: oklch(0.56 0.184 159.5);
  --brand-700: oklch(0.48 0.173 159.5);
  --brand-800: oklch(0.40 0.155 159.5);
  --brand-900: oklch(0.32 0.129 159.5);
  --brand-950: oklch(0.24 0.101 159.5);
}

Colors that work with #40fbab

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#F4FAF8
Tinted page background
Border#C0EDD9
Hairlines and dividers
Muted text#4B9B79
Captions on the surface
Accent#CC008A
Second voice, not a rival
Dark variant#037D49
Hover, pressed, headers
Light variant#E6FEF4
Selected rows, tints
Dark surface#14241D
Dark-mode background
Hover#1DFA9C
One step down in lightness
Pressed#05EF8B
Two steps down
Disabled#CDDFD7
Chroma pulled out
Focus ring#51FFB4
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 #40fbab

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 #037D49
Safe as a 1px border on white
No — use #04A962

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.

At this chroma the association is amplified — it will dominate anything placed beside it, so give it space and use it sparingly. 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
  • FormalityLow
  • EnergyHigh
  • Weight38/100
  • 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#FB4090
Analogous left#40FB4E
Analogous right#40EEFB
Split-complement 1#FB40EE
Split-complement 2#FB4E40
Triadic 1#AB40FB
Triadic 2#FBAB40
Tetradic#4E40FB
On the wheel
Base+30°−30°+120°+240°+180°154°

#40fbab sits at 154°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red25.1%
Green98.4%
Blue67.1%
R · 0–255
64
0x40
G · 0–255
251
0xfb
B · 0–255
171
0xab

CMYK percentages

Cyan74.5%
Magenta0.0%
Yellow31.9%
Key (black)1.6%

Total ink coverage is 108%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#40fbab text on a black background

contrast 15.60:1

Card sample

#40fbab text on a white background

contrast 1.35:1

Card sample

#40fbab on grey

1.23:1

#40fbab on its own surface

1.27:1

#40fbab on its dark surface

12.01:1

CSS3 live lab

Text font color

The quick brown fox

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

Glowing headline

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

Soft neon halo

text-shadow: 0 0 14px rgba(64, 251, 171, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(64, 251, 171, 0.45);
Border & gradient
Gradient panel
border: 3px solid #40fbab;
background: linear-gradient(135deg, #40fbab, #40CEFB);
Gradient text

Gradient headline

background: linear-gradient(90deg, #40fbab, #40A0FB);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #40fbab;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #40fbab;
caret-color: #40fbab;
Left rule
Pull quote or callout
border-left: 4px solid #40fbab;
Ring + tint
Selected chip
background: #E6FEF4;
box-shadow: inset 0 0 0 2px #40fbab;
Conic badge
68%
background: conic-gradient(#40fbab 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #40fbab 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, 251, 171, 0.5)
rgb(64 251 171 / 50%)
#40fbab80
hsl(154 96% 62% / 50%)
color-mix(in srgb, #40fbab 50%, transparent)
Alpha8-digit hexFlat on white
10%#40fbab1a#ECFFF7
20%#40fbab33#D9FEEE
40%#40fbab66#B3FDDD
60%#40fbab99#8CFDCD
80%#40fbabcc#66FCBC

Gradients from #40fbab

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, #7CFCC5, #40fbab 45%, #037D49);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #40fbab, #22B5FA);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #40fbab, #FB4090);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #9AFDD3 0%, #40fbab 45%, #037D49 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4FAF8, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #74FC72 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #5EE3FC 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #037D49 0%, transparent 65%), #40fbab;

Monochromatic scale

Palettes built from #40fbab

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.

#40fbab 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.

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 15.60:1.

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.

#40fbab, answered

What color is #40fbab?

#40fbab is a balanced electric green, closest to Medium Spring Green (ΔE2000 2.7). It sits at 154° on the hue wheel with 96% saturation and 62% lightness, which reads as cool.

What is the RGB value of #40fbab?

rgb(64, 251, 171) — 64 red, 251 green and 171 blue out of 255, or 25.1% / 98.4% / 67.1% by channel.

What is #40fbab in HSL and HSV?

hsl(154, 96%, 62%) and hsv(154, 75%, 98%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #40fbab a light or a dark color?

It is a light color. Relative luminance is 0.7302 and perceived brightness is 80%, so black text on it reaches 15.60:1.

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

Black. It scores 15.60:1 against #40fbab, versus 1.35:1 for white — AAA at any size.

Is #40fbab accessible on a white background?

#40fbab on white scores 1.35:1, which fails WCAG AA at every size. Darken it to #03864E to reach 4.5:1, or #026339 for 7:1.

What is the complementary color of #40fbab?

#FB4090 sits directly opposite on the wheel. Softer options are the split-complements #FB40EE and #FB4E40, which give the same contrast with far less vibration.

What colors go well with #40fbab?

For interface work: #F4FAF8 as the surface, #C0EDD9 for borders, #4B9B79 for secondary text, #CC008A as an accent and #037D49 for hover and pressed states. For a palette, the analogous pair #40FB4E and #40EEFB stays calm, while #FB4090 is the loudest partner.

What is #40fbab in CMYK for printing?

cmyk(75%, 0%, 32%, 2%). 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 #40fbab warm or cool?

Cool — it scores 77 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #40FB66; nudged cooler, #3EFDF1.

Which Tailwind color is closest to #40fbab?

The green family — its 500 step is #22c55e, ΔE2000 14 away. That is a visible difference, so define #40fbab as a custom token rather than reaching for the built-in.

How do I use #40fbab in Tailwind CSS?

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

rgba(64, 251, 171, 0.5), or #40fbab80 in eight-digit hex. Over white that composites to #A0FDD5; over black, #207E56.

Is #40fbab a web-safe color?

No. The nearest web-safe colour is #33FF99, ΔE2000 3.5 away. The palette only matters for legacy displays and some email clients now.

What does the color #40fbab 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 #40fbab?

The safest is same-hue elevation: linear-gradient(135deg, #7CFCC5, #40fbab 45%, #037D49). For more colour, a short hue run to #22B5FA keeps it rich without turning muddy.

Work with #40fbab in the Color Lab

Every tool opens with this colour already loaded.

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