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cyan · cool

#40cd9f

a balanced, vivid cyan · cool · closest name: Medium Aqua Marine

Token name suggestion: Atlas Glacier

RGB
64, 205, 159
HSL
160°, 59%, 53%
CMYK
69, 0, 22, 20
Luminance
0.4726

#40cd9f is a balanced vivid cyan, 160° on the wheel and 79/100 on the cool side. Put black text on it (10.45:1). As text it scores 2.01:1 on white — use #238464 instead. Nearest name is Medium Aqua Marine, nearest Tailwind family is emerald.

hsl(160 59% 53%)rgb(64 205 159)Base step 500AAA inkCool

At a glance

Every number on this page in one read: what #40cd9f is made of, how bright it looks, and which way it leans.

Hex
#40cd9f
Hue
160°
cyan
Saturation
59%
vivid
Lightness
53%
balanced
Brightness
80%
HSV value
Perceived
67%
weighted brightness
Luminance
0.4726
WCAG relative
Temperature
Cool
79/100 cool
Color family
Cyan
Tone
Vivid
Best ink
Black
10.45:1
Closest name
Medium Aqua Marine
ΔE2000 3.7
Chroma
49.8
LCH, 0–130ish
OKLCH L
0.762
perceptual lightness
Tailwind
emerald
500 · ΔE 6.4
Web-safe
#33CC99
nearest of 216
Where it sits
Hue160° of 360°
Saturation59%
Lightness53%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #40cd9f.

Temperature
Warm ← → Cool79% 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%
Green92%
Blue5%

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

Every format

HEX#40cd9f
HEX (8-digit)#40cd9fff
RGBrgb(64, 205, 159)
RGBArgba(64, 205, 159, 1)
HSLhsl(160, 59%, 53%)
HSV / HSBhsv(160, 69%, 80%)
HWBhwb(160 25% 20%)
CMYKcmyk(69%, 0%, 22%, 20%)
LABlab(74.3 -48.3 12.2)
LCHlch(74.3 49.8 165.9)
OKLCHoklch(0.762 0.137 166.9)
XYZ (D65)xyz(30.20, 47.25, 40.32)
Decimal4246943
Display P3color(display-p3 0.251 0.804 0.624)
Web-safe#33CC99

Copy-ready code

every platformclick to select
/* CSS */
color: #40cd9f;
background-color: #40cd9f;
/* CSS custom property */
--brand: #40cd9f;
/* Tailwind (arbitrary) */
class="text-[#40cd9f] bg-[#40cd9f]"
/* SCSS */
$brand: #40cd9f;
/* SwiftUI */
Color(red: 0.251, green: 0.804, blue: 0.624)
/* UIKit */
UIColor(red: 0.251, green: 0.804, blue: 0.624, alpha: 1)
/* Android XML */
<color name="brand">#40CD9F</color>
/* Android Compose */
Color(0xFF40CD9F)
/* Flutter */
Color(0xFF40CD9F)
/* Python / OpenCV (BGR) */
(159, 205, 64)
/* Python / PIL (RGB) */
(64, 205, 159)
/* Java AWT */
new Color(64, 205, 159)
/* .NET */
Color.FromArgb(255, 64, 205, 159)
/* OpenGL / Unity (0–1) */
(0.2510f, 0.8039f, 0.6235f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{64,205,159}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #40cd9f 85%, white);
border-color: color-mix(in oklab, #40cd9f 40%, transparent);
/* theme-aware in one line */
color: light-dark(#1A654D, #D3EEE5);
/* relative colour syntax */
--hover: hsl(from #40cd9f 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: #F4FBF9;
  --brand-100: #E9F7F2;
  --brand-200: #CDEFE4;
  --brand-300: #A6E8D2;
  --brand-400: #7ADCBC;
  --brand-500: #40cd9f;
  --brand-600: #33C293;
  --brand-700: #2AA27B;
  --brand-800: #228162;
  --brand-900: #1C5E49;
  --brand-950: #123B2D;
  --brand: #40cd9f;
  --brand-ink: #000000;
  --brand-surface: #F4FAF8;
  --brand-border: #C0EDDE;
  --brand-hover: #30B98C;
  --brand-pressed: #299C77;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #14241F;
    --brand-ink: #D3EEE5;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F4FBF9',
        100: '#E9F7F2',
        200: '#CDEFE4',
        300: '#A6E8D2',
        400: '#7ADCBC',
        500: '#40cd9f',
        600: '#33C293',
        700: '#2AA27B',
        800: '#228162',
        900: '#1C5E49',
        950: '#123B2D',
        DEFAULT: '#40cd9f',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F4FBF9,
  '100': #E9F7F2,
  '200': #CDEFE4,
  '300': #A6E8D2,
  '400': #7ADCBC,
  '500': #40cd9f,
  '600': #33C293,
  '700': #2AA27B,
  '800': #228162,
  '900': #1C5E49,
  '950': #123B2D,
);
$brand-base: #40cd9f;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F4FBF9", "$type": "color" },
      "100": { "$value": "#E9F7F2", "$type": "color" },
      "200": { "$value": "#CDEFE4", "$type": "color" },
      "300": { "$value": "#A6E8D2", "$type": "color" },
      "400": { "$value": "#7ADCBC", "$type": "color" },
      "500": { "$value": "#40cd9f", "$type": "color" },
      "600": { "$value": "#33C293", "$type": "color" },
      "700": { "$value": "#2AA27B", "$type": "color" },
      "800": { "$value": "#228162", "$type": "color" },
      "900": { "$value": "#1C5E49", "$type": "color" },
      "950": { "$value": "#123B2D", "$type": "color" }
    },
    "brandInk": { "$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 #40cd9f · 10.45:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 2.01:1
AA fail · AA large fail · AAA fail
Aa
Black text · 10.45:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #40cd9f as text scores 2.01:1 on white and 10.45:1 on black.
Best tinted ink on it, if plain black or white feels flat: #1A654D at 3.47:1.

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
#238464 · 4.61:1
AA on white−20% L
#238464
The quick fox
#1A644C · 7.07:1
AAA on white−28% L
#1A644C
The quick fox
#40cd9f · 10.45:1
AA on blackalready passes
#40cd9f
The quick fox
#40cd9f · 10.45:1
AAA on blackalready passes
#40cd9f

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #2BA47D 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
#40cd9f on white: 2.01:1
AA ✗ fail · AA-large · AAA
Aa
#40cd9f on black: 10.45:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #40cd9f as text on that neutral, and that neutral as text on #40cd9f.

NeutralRatioBoth directions
White2.01:1AaAa
Slate 501.92:1AaAa
Slate 1001.83:1AaAa
Slate 2001.63:1AaAa
Slate 3001.35:1AaAa
Slate 4001.28:1AaAa
Slate 5002.37:1AaAa
Slate 6003.77:1AaAa
Slate 7005.15:1AaAa
Slate 8007.28:1AaAa
Slate 9008.88:1AaAa
Black10.45:1AaAa
Colour vision deficiency
true color
protanopia · #C8BF9D
deuteranopia · #B6B1A2
tritanopia · #00CEC0

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. #40cd9f 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.

#F4FBF9
#E9F7F2
#CDEFE4
#A6E8D2
#7ADCBC
#40cd9f
#33C293
#2AA27B
#228162
#1C5E49
#123B2D
Base = 500Lightest = 50 · #F4FBF9Darkest = 950 · #123B2DText step on white = 800
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 0.034 166.9);
  --brand-100: oklch(0.94 0.055 166.9);
  --brand-200: oklch(0.88 0.082 166.9);
  --brand-300: oklch(0.80 0.107 166.9);
  --brand-400: oklch(0.72 0.126 166.9);
  --brand-500: oklch(0.64 0.137 166.9);
  --brand-600: oklch(0.56 0.137 166.9);
  --brand-700: oklch(0.48 0.129 166.9);
  --brand-800: oklch(0.40 0.115 166.9);
  --brand-900: oklch(0.32 0.096 166.9);
  --brand-950: oklch(0.24 0.076 166.9);
}

Colors that work with #40cd9f

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#C0EDDE
Hairlines and dividers
Muted text#4B9B81
Captions on the surface
Accent#D23B92
Second voice, not a rival
Dark variant#1A654D
Hover, pressed, headers
Light variant#EBFAF5
Selected rows, tints
Dark surface#14241F
Dark-mode background
Hover#30B98C
One step down in lightness
Pressed#299C77
Two steps down
Disabled#B0CDC3
Chroma pulled out
Focus ring#45DCAB
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 #40cd9f

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
  • Thin strokes and 1px borders — they disappear on light UI
  • 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 #1A654D
Safe as a 1px border on white
No — use #2BA47D

Meaning and mood

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

cleantechnicalfreshclinical

Cyan reads as water, air and infrastructure: cool, hygienic, engineered.

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

At high lightness it disappears into white surfaces and thin strokes vanish entirely.

Reads as
  • FormalityMedium
  • EnergyMedium-high
  • Weight47/100
  • 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#CD406E
Analogous left#40CD58
Analogous right#40B4CD
Split-complement 1#CD40B4
Split-complement 2#CD5840
Triadic 1#9F40CD
Triadic 2#CD9F40
Tetradic#5840CD
On the wheel
Base+30°−30°+120°+240°+180°160°

#40cd9f sits at 160°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red25.1%
Green80.4%
Blue62.4%
R · 0–255
64
0x40
G · 0–255
205
0xcd
B · 0–255
159
0x9f

CMYK percentages

Cyan68.8%
Magenta0.0%
Yellow22.4%
Key (black)19.6%

Total ink coverage is 111%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#40cd9f text on a black background

contrast 10.45:1

Card sample

#40cd9f text on a white background

contrast 2.01:1

Card sample

#40cd9f on grey

1.83:1

#40cd9f on its own surface

1.90:1

#40cd9f on its dark surface

8.03:1

CSS3 live lab

Text font color

The quick brown fox

color: #40cd9f;
Background color
Panel with #40cd9f background
background-color: #40cd9f;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #40cd9f;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(64, 205, 159, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(64, 205, 159, 0.45);
Border & gradient
Gradient panel
border: 3px solid #40cd9f;
background: linear-gradient(135deg, #40cd9f, #409DCD);
Gradient text

Gradient headline

background: linear-gradient(90deg, #40cd9f, #407ACD);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #40cd9f;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #40cd9f;
caret-color: #40cd9f;
Left rule
Pull quote or callout
border-left: 4px solid #40cd9f;
Ring + tint
Selected chip
background: #EBFAF5;
box-shadow: inset 0 0 0 2px #40cd9f;
Conic badge
68%
background: conic-gradient(#40cd9f 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #40cd9f 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, 205, 159, 0.5)
rgb(64 205 159 / 50%)
#40cd9f80
hsl(160 59% 53% / 50%)
color-mix(in srgb, #40cd9f 50%, transparent)
Alpha8-digit hexFlat on white
10%#40cd9f1a#ECFAF5
20%#40cd9f33#D9F5EC
40%#40cd9f66#B3EBD9
60%#40cd9f99#8CE1C5
80%#40cd9fcc#66D7B2

Gradients from #40cd9f

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, #70DAB7, #40cd9f 45%, #1A654D);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #40cd9f, #3182BD);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #40cd9f, #CD406E);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #89E0C3 0%, #40cd9f 45%, #1A654D 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%, #68D872 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #58B4D3 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #1A654D 0%, transparent 65%), #40cd9f;

Monochromatic scale

Palettes built from #40cd9f

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.

#40cd9f in the real world

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

Industries
TechnologyTravelHealthcareMedia
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 10.45:1.

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.

#40cd9f, answered

What color is #40cd9f?

#40cd9f is a balanced vivid cyan, closest to Medium Aqua Marine (ΔE2000 3.7). It sits at 160° on the hue wheel with 59% saturation and 53% lightness, which reads as cool.

What is the RGB value of #40cd9f?

rgb(64, 205, 159) — 64 red, 205 green and 159 blue out of 255, or 25.1% / 80.4% / 62.4% by channel.

What is #40cd9f in HSL and HSV?

hsl(160, 59%, 53%) and hsv(160, 69%, 80%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #40cd9f a light or a dark color?

It is a mid-tone. Relative luminance is 0.4726 and perceived brightness is 67%, so black text on it reaches 10.45:1.

Should I use black or white text on #40cd9f?

Black. It scores 10.45:1 against #40cd9f, versus 2.01:1 for white — AAA at any size.

Is #40cd9f accessible on a white background?

#40cd9f on white scores 2.01:1, which fails WCAG AA at every size. Darken it to #238464 to reach 4.5:1, or #1A644C for 7:1.

What is the complementary color of #40cd9f?

#CD406E sits directly opposite on the wheel. Softer options are the split-complements #CD40B4 and #CD5840, which give the same contrast with far less vibration.

What colors go well with #40cd9f?

For interface work: #F4FAF8 as the surface, #C0EDDE for borders, #4B9B81 for secondary text, #D23B92 as an accent and #1A654D for hover and pressed states. For a palette, the analogous pair #40CD58 and #40B4CD stays calm, while #CD406E is the loudest partner.

What is #40cd9f in CMYK for printing?

cmyk(69%, 0%, 22%, 20%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #40cd9f warm or cool?

Cool — it scores 79 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #40CD6B; nudged cooler, #3DCACF.

Which Tailwind color is closest to #40cd9f?

The emerald family — its 500 step is #10b981, ΔE2000 6.4 away. That is a visible difference, so define #40cd9f as a custom token rather than reaching for the built-in.

How do I use #40cd9f in Tailwind CSS?

Inline it as an arbitrary value with bg-[#40cd9f] or text-[#40cd9f], 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 #40cd9f with 50% opacity?

rgba(64, 205, 159, 0.5), or #40cd9f80 in eight-digit hex. Over white that composites to #A0E6CF; over black, #206750.

Is #40cd9f a web-safe color?

No. The nearest web-safe colour is #33CC99, ΔE2000 1.3 away. The palette only matters for legacy displays and some email clients now.

What does the color #40cd9f mean?

As a cyan, it reads clean, technical, fresh. Cyan reads as water, air and infrastructure: cool, hygienic, engineered. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #40cd9f?

The safest is same-hue elevation: linear-gradient(135deg, #70DAB7, #40cd9f 45%, #1A654D). For more colour, a short hue run to #3182BD keeps it rich without turning muddy.

Work with #40cd9f in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #40cd9f at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.