Skip to content
cyan · cool

#37e2df

a balanced, vivid cyan · cool · closest name: Medium Turquoise

Token name suggestion: Atlas Reef

RGB
55, 226, 223
HSL
179°, 75%, 55%
CMYK
76, 0, 1, 11
Luminance
0.6053

#37e2df is a balanced vivid cyan, 179° on the wheel and 87/100 on the cool side. Put black text on it (13.11:1). As text it scores 1.60:1 on white — use #138280 instead. Nearest name is Medium Turquoise, nearest Tailwind family is teal.

hsl(179 75% 55%)rgb(55 226 223)Base step 500AAA inkCool

At a glance

Every number on this page in one read: what #37e2df is made of, how bright it looks, and which way it leans.

Hex
#37e2df
Hue
179°
cyan
Saturation
75%
vivid
Lightness
55%
balanced
Brightness
89%
HSV value
Perceived
75%
weighted brightness
Luminance
0.6053
WCAG relative
Temperature
Cool
87/100 cool
Color family
Cyan
Tone
Vivid
Best ink
Black
13.11:1
Closest name
Medium Turquoise
ΔE2000 4.1
Chroma
43.2
LCH, 0–130ish
OKLCH L
0.830
perceptual lightness
Tailwind
teal
500 · ΔE 12.1
Web-safe
#33CCCC
nearest of 216
Where it sits
Hue179° of 360°
Saturation75%
Lightness55%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #37e2df.

Temperature
Warm ← → Cool87% 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%
Green90%
Blue9%

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

Every format

HEX#37e2df
HEX (8-digit)#37e2dfff
RGBrgb(55, 226, 223)
RGBArgba(55, 226, 223, 1)
HSLhsl(179, 75%, 55%)
HSV / HSBhsv(179, 76%, 89%)
HWBhwb(179 22% 11%)
CMYKcmyk(76%, 0%, 1%, 11%)
LABlab(82.1 -41.9 -10.7)
LCHlch(82.1 43.2 194.4)
OKLCHoklch(0.830 0.132 193.1)
XYZ (D65)xyz(42.08, 60.53, 79.26)
Decimal3662559
Display P3color(display-p3 0.216 0.886 0.875)
Web-safe#33CCCC

Copy-ready code

every platformclick to select
/* CSS */
color: #37e2df;
background-color: #37e2df;
/* CSS custom property */
--brand: #37e2df;
/* Tailwind (arbitrary) */
class="text-[#37e2df] bg-[#37e2df]"
/* SCSS */
$brand: #37e2df;
/* SwiftUI */
Color(red: 0.216, green: 0.886, blue: 0.875)
/* UIKit */
UIColor(red: 0.216, green: 0.886, blue: 0.875, alpha: 1)
/* Android XML */
<color name="brand">#37E2DF</color>
/* Android Compose */
Color(0xFF37E2DF)
/* Flutter */
Color(0xFF37E2DF)
/* Python / OpenCV (BGR) */
(223, 226, 55)
/* Python / PIL (RGB) */
(55, 226, 223)
/* Java AWT */
new Color(55, 226, 223)
/* .NET */
Color.FromArgb(255, 55, 226, 223)
/* OpenGL / Unity (0–1) */
(0.2157f, 0.8863f, 0.8745f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{55,226,223}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #37e2df 85%, white);
border-color: color-mix(in oklab, #37e2df 40%, transparent);
/* theme-aware in one line */
color: light-dark(#106F6E, #D3EEEE);
/* relative colour syntax */
--hover: hsl(from #37e2df 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: #F3FCFC;
  --brand-100: #E7F9F8;
  --brand-200: #C8F4F3;
  --brand-300: #9DF1EF;
  --brand-400: #6CEAE7;
  --brand-500: #37e2df;
  --brand-600: #1FD6D2;
  --brand-700: #1AB2AF;
  --brand-800: #158F8C;
  --brand-900: #136766;
  --brand-950: #0C4140;
  --brand: #37e2df;
  --brand-ink: #000000;
  --brand-surface: #F4FAFA;
  --brand-border: #C0EDEC;
  --brand-hover: #1FD6D3;
  --brand-pressed: #1BB7B4;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142424;
    --brand-ink: #D3EEEE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F3FCFC',
        100: '#E7F9F8',
        200: '#C8F4F3',
        300: '#9DF1EF',
        400: '#6CEAE7',
        500: '#37e2df',
        600: '#1FD6D2',
        700: '#1AB2AF',
        800: '#158F8C',
        900: '#136766',
        950: '#0C4140',
        DEFAULT: '#37e2df',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F3FCFC,
  '100': #E7F9F8,
  '200': #C8F4F3,
  '300': #9DF1EF,
  '400': #6CEAE7,
  '500': #37e2df,
  '600': #1FD6D2,
  '700': #1AB2AF,
  '800': #158F8C,
  '900': #136766,
  '950': #0C4140,
);
$brand-base: #37e2df;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F3FCFC", "$type": "color" },
      "100": { "$value": "#E7F9F8", "$type": "color" },
      "200": { "$value": "#C8F4F3", "$type": "color" },
      "300": { "$value": "#9DF1EF", "$type": "color" },
      "400": { "$value": "#6CEAE7", "$type": "color" },
      "500": { "$value": "#37e2df", "$type": "color" },
      "600": { "$value": "#1FD6D2", "$type": "color" },
      "700": { "$value": "#1AB2AF", "$type": "color" },
      "800": { "$value": "#158F8C", "$type": "color" },
      "900": { "$value": "#136766", "$type": "color" },
      "950": { "$value": "#0C4140", "$type": "color" }
    },
    "brandInk": { "$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 #37e2df · 13.11:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.60:1
AA fail · AA large fail · AAA fail
Aa
Black text · 13.11:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #37e2df as text scores 1.60:1 on white and 13.11:1 on black.
Best tinted ink on it, if plain black or white feels flat: #106F6E at 3.72:1.

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
#138280 · 4.63:1
AA on white−26% L
#138280
The quick fox
#0E6261 · 7.15:1
AAA on white−33% L
#0E6261
The quick fox
#37e2df · 13.11:1
AA on blackalready passes
#37e2df
The quick fox
#37e2df · 13.11:1
AAA on blackalready passes
#37e2df

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #18A5A3 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
#37e2df on white: 1.60:1
AA ✗ fail · AA-large · AAA
Aa
#37e2df on black: 13.11:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #37e2df as text on that neutral, and that neutral as text on #37e2df.

NeutralRatioBoth directions
White1.60:1AaAa
Slate 501.53:1AaAa
Slate 1001.46:1AaAa
Slate 2001.30:1AaAa
Slate 3001.08:1AaAa
Slate 4001.60:1AaAa
Slate 5002.97:1AaAa
Slate 6004.73:1AaAa
Slate 7006.46:1AaAa
Slate 8009.13:1AaAa
Slate 90011.14:1AaAa
Black13.11:1AaAa
Colour vision deficiency
true color
protanopia · #D4D6DF
deuteranopia · #BCC5E0
tritanopia · #00E9E1

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. #37e2df 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.

#F3FCFC
#E7F9F8
#C8F4F3
#9DF1EF
#6CEAE7
#37e2df
#1FD6D2
#1AB2AF
#158F8C
#136766
#0C4140
Base = 500Lightest = 50 · #F3FCFCDarkest = 950 · #0C4140Text 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 0.033 193.1);
  --brand-100: oklch(0.94 0.053 193.1);
  --brand-200: oklch(0.88 0.079 193.1);
  --brand-300: oklch(0.80 0.103 193.1);
  --brand-400: oklch(0.72 0.122 193.1);
  --brand-500: oklch(0.64 0.132 193.1);
  --brand-600: oklch(0.56 0.132 193.1);
  --brand-700: oklch(0.48 0.124 193.1);
  --brand-800: oklch(0.40 0.111 193.1);
  --brand-900: oklch(0.32 0.092 193.1);
  --brand-950: oklch(0.24 0.073 193.1);
}

Colors that work with #37e2df

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#F4FAFA
Tinted page background
Border#C0EDEC
Hairlines and dividers
Muted text#4B9B99
Captions on the surface
Accent#E73263
Second voice, not a rival
Dark variant#106F6E
Hover, pressed, headers
Light variant#E9FCFB
Selected rows, tints
Dark surface#142424
Dark-mode background
Hover#1FD6D3
One step down in lightness
Pressed#1BB7B4
Two steps down
Disabled#B8D1D1
Chroma pulled out
Focus ring#3EEFEC
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 #37e2df

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 #106F6E
Safe as a 1px border on white
No — use #18A5A3

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
  • Weight45/100
  • 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#E2373A
Analogous left#37E289
Analogous right#3790E2
Split-complement 1#E23790
Split-complement 2#E28937
Triadic 1#DF37E2
Triadic 2#E2DF37
Tetradic#8937E2
On the wheel
Base+30°−30°+120°+240°+180°179°

#37e2df sits at 179°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red21.6%
Green88.6%
Blue87.5%
R · 0–255
55
0x37
G · 0–255
226
0xe2
B · 0–255
223
0xdf

CMYK percentages

Cyan75.7%
Magenta0.0%
Yellow1.3%
Key (black)11.4%

Total ink coverage is 88%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#37e2df text on a black background

contrast 13.11:1

Card sample

#37e2df text on a white background

contrast 1.60:1

Card sample

#37e2df on grey

1.46:1

#37e2df on its own surface

1.52:1

#37e2df on its dark surface

10.02:1

CSS3 live lab

Text font color

The quick brown fox

color: #37e2df;
Background color
Panel with #37e2df background
background-color: #37e2df;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #37e2df;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(55, 226, 223, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(55, 226, 223, 0.45);
Border & gradient
Gradient panel
border: 3px solid #37e2df;
background: linear-gradient(135deg, #37e2df, #3773E2);
Gradient text

Gradient headline

background: linear-gradient(90deg, #37e2df, #3748E2);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #37e2df;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #37e2df;
caret-color: #37e2df;
Left rule
Pull quote or callout
border-left: 4px solid #37e2df;
Ring + tint
Selected chip
background: #E9FCFB;
box-shadow: inset 0 0 0 2px #37e2df;
Conic badge
68%
background: conic-gradient(#37e2df 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #37e2df 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(55, 226, 223, 0.5)
rgb(55 226 223 / 50%)
#37e2df80
hsl(179 75% 55% / 50%)
color-mix(in srgb, #37e2df 50%, transparent)
Alpha8-digit hexFlat on white
10%#37e2df1a#EBFCFC
20%#37e2df33#D7F9F9
40%#37e2df66#AFF3F2
60%#37e2df99#87EEEC
80%#37e2dfcc#5FE8E5

Gradients from #37e2df

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, #6CEAE7, #37e2df 45%, #106F6E);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #37e2df, #2052DB);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #37e2df, #E2373A);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #87EEEC 0%, #37e2df 45%, #106F6E 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4FAFA, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #64E898 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #5292E6 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #106F6E 0%, transparent 65%), #37e2df;

Monochromatic scale

Palettes built from #37e2df

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.

#37e2df 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 13.11:1.

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.

#37e2df, answered

What color is #37e2df?

#37e2df is a balanced vivid cyan, closest to Medium Turquoise (ΔE2000 4.1). It sits at 179° on the hue wheel with 75% saturation and 55% lightness, which reads as cool.

What is the RGB value of #37e2df?

rgb(55, 226, 223) — 55 red, 226 green and 223 blue out of 255, or 21.6% / 88.6% / 87.5% by channel.

What is #37e2df in HSL and HSV?

hsl(179, 75%, 55%) and hsv(179, 76%, 89%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #37e2df a light or a dark color?

It is a light color. Relative luminance is 0.6053 and perceived brightness is 75%, so black text on it reaches 13.11:1.

Should I use black or white text on #37e2df?

Black. It scores 13.11:1 against #37e2df, versus 1.60:1 for white — AAA at any size.

Is #37e2df accessible on a white background?

#37e2df on white scores 1.60:1, which fails WCAG AA at every size. Darken it to #138280 to reach 4.5:1, or #0E6261 for 7:1.

What is the complementary color of #37e2df?

#E2373A sits directly opposite on the wheel. Softer options are the split-complements #E23790 and #E28937, which give the same contrast with far less vibration.

What colors go well with #37e2df?

For interface work: #F4FAFA as the surface, #C0EDEC for borders, #4B9B99 for secondary text, #E73263 as an accent and #106F6E for hover and pressed states. For a palette, the analogous pair #37E289 and #3790E2 stays calm, while #E2373A is the loudest partner.

What is #37e2df in CMYK for printing?

cmyk(76%, 0%, 1%, 11%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #37e2df warm or cool?

Cool — it scores 87 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #37E2A0; nudged cooler, #35B4E4.

Which Tailwind color is closest to #37e2df?

The teal family — its 500 step is #14b8a6, ΔE2000 12.1 away. That is a visible difference, so define #37e2df as a custom token rather than reaching for the built-in.

How do I use #37e2df in Tailwind CSS?

Inline it as an arbitrary value with bg-[#37e2df] or text-[#37e2df], 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 #37e2df with 50% opacity?

rgba(55, 226, 223, 0.5), or #37e2df80 in eight-digit hex. Over white that composites to #9BF1EF; over black, #1C7170.

Is #37e2df a web-safe color?

No. The nearest web-safe colour is #33CCCC, ΔE2000 5.3 away. The palette only matters for legacy displays and some email clients now.

What does the color #37e2df 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 #37e2df?

The safest is same-hue elevation: linear-gradient(135deg, #6CEAE7, #37e2df 45%, #106F6E). For more colour, a short hue run to #2052DB keeps it rich without turning muddy.

Work with #37e2df in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #37e2df at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.