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cyan · cool

#37bfef

a balanced, electric cyan · cool · closest name: Deep Sky Blue

Token name suggestion: Atlas Teal

RGB
55, 191, 239
HSL
196°, 85%, 58%
CMYK
77, 20, 0, 6
Luminance
0.4431

#37bfef is a balanced electric cyan, 196° on the wheel and 94/100 on the cool side. Put black text on it (9.86:1). As text it scores 2.13:1 on white — use #0D80A8 instead. Nearest name is Deep Sky Blue, nearest Tailwind family is cyan.

hsl(196 85% 58%)rgb(55 191 239)Base step 500AAA inkCool

At a glance

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

Hex
#37bfef
Hue
196°
cyan
Saturation
85%
electric
Lightness
58%
balanced
Brightness
94%
HSV value
Perceived
67%
weighted brightness
Luminance
0.4431
WCAG relative
Temperature
Cool
94/100 cool
Color family
Cyan
Tone
Electric
Best ink
Black
9.86:1
Closest name
Deep Sky Blue
ΔE2000 3.4
Chroma
39.6
LCH, 0–130ish
OKLCH L
0.754
perceptual lightness
Tailwind
cyan
500 · ΔE 6.6
Web-safe
#33CCFF
nearest of 216
Where it sits
Hue196° of 360°
Saturation85%
Lightness58%
Saturation × lightness field

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

Temperature
Warm ← → Cool94% 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%
Green84%
Blue14%

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

Every format

HEX#37bfef
HEX (8-digit)#37bfefff
RGBrgb(55, 191, 239)
RGBArgba(55, 191, 239, 1)
HSLhsl(196, 85%, 58%)
HSV / HSBhsv(196, 77%, 94%)
HWBhwb(196 22% 6%)
CMYKcmyk(77%, 20%, 0%, 6%)
LABlab(72.4 -20.1 -34.0)
LCHlch(72.4 39.6 239.4)
OKLCHoklch(0.754 0.131 226.9)
XYZ (D65)xyz(35.78, 44.30, 88.31)
Decimal3653615
Display P3color(display-p3 0.216 0.749 0.937)
Web-safe#33CCFF

Copy-ready code

every platformclick to select
/* CSS */
color: #37bfef;
background-color: #37bfef;
/* CSS custom property */
--brand: #37bfef;
/* Tailwind (arbitrary) */
class="text-[#37bfef] bg-[#37bfef]"
/* SCSS */
$brand: #37bfef;
/* SwiftUI */
Color(red: 0.216, green: 0.749, blue: 0.937)
/* UIKit */
UIColor(red: 0.216, green: 0.749, blue: 0.937, alpha: 1)
/* Android XML */
<color name="brand">#37BFEF</color>
/* Android Compose */
Color(0xFF37BFEF)
/* Flutter */
Color(0xFF37BFEF)
/* Python / OpenCV (BGR) */
(239, 191, 55)
/* Python / PIL (RGB) */
(55, 191, 239)
/* Java AWT */
new Color(55, 191, 239)
/* .NET */
Color.FromArgb(255, 55, 191, 239)
/* OpenGL / Unity (0–1) */
(0.2157f, 0.7490f, 0.9373f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{55,191,239}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #37bfef 85%, white);
border-color: color-mix(in oklab, #37bfef 40%, transparent);
/* theme-aware in one line */
color: light-dark(#095A76, #D3E7EE);
/* relative colour syntax */
--hover: hsl(from #37bfef 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: #F2FAFC;
  --brand-100: #E5F5FA;
  --brand-200: #C5EAF7;
  --brand-300: #97DEF7;
  --brand-400: #63CDF3;
  --brand-500: #37bfef;
  --brand-600: #12ACE3;
  --brand-700: #0F8FBD;
  --brand-800: #0C7397;
  --brand-900: #0D546D;
  --brand-950: #083544;
  --brand: #37bfef;
  --brand-ink: #000000;
  --brand-surface: #F4F9FA;
  --brand-border: #C0E1ED;
  --brand-hover: #16B4EC;
  --brand-pressed: #109CCE;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142024;
    --brand-ink: #D3E7EE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F2FAFC',
        100: '#E5F5FA',
        200: '#C5EAF7',
        300: '#97DEF7',
        400: '#63CDF3',
        500: '#37bfef',
        600: '#12ACE3',
        700: '#0F8FBD',
        800: '#0C7397',
        900: '#0D546D',
        950: '#083544',
        DEFAULT: '#37bfef',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F2FAFC,
  '100': #E5F5FA,
  '200': #C5EAF7,
  '300': #97DEF7,
  '400': #63CDF3,
  '500': #37bfef,
  '600': #12ACE3,
  '700': #0F8FBD,
  '800': #0C7397,
  '900': #0D546D,
  '950': #083544,
);
$brand-base: #37bfef;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F2FAFC", "$type": "color" },
      "100": { "$value": "#E5F5FA", "$type": "color" },
      "200": { "$value": "#C5EAF7", "$type": "color" },
      "300": { "$value": "#97DEF7", "$type": "color" },
      "400": { "$value": "#63CDF3", "$type": "color" },
      "500": { "$value": "#37bfef", "$type": "color" },
      "600": { "$value": "#12ACE3", "$type": "color" },
      "700": { "$value": "#0F8FBD", "$type": "color" },
      "800": { "$value": "#0C7397", "$type": "color" },
      "900": { "$value": "#0D546D", "$type": "color" },
      "950": { "$value": "#083544", "$type": "color" }
    },
    "brandInk": { "$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 #37bfef · 9.86:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 2.13:1
AA fail · AA large fail · AAA fail
Aa
Black text · 9.86:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #37bfef as text scores 2.13:1 on white and 9.86:1 on black.
Best tinted ink on it, if plain black or white feels flat: #095A76 at 3.60:1.

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
#0D80A8 · 4.50:1
AA on white−22% L
#0D80A8
The quick fox
#0A5F7E · 7.12:1
AAA on white−31% L
#0A5F7E
The quick fox
#37bfef · 9.86:1
AA on blackalready passes
#37bfef
The quick fox
#37bfef · 9.86:1
AAA on blackalready passes
#37bfef

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #11A0D3 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
#37bfef on white: 2.13:1
AA ✗ fail · AA-large · AAA
Aa
#37bfef on black: 9.86:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

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

NeutralRatioBoth directions
White2.13:1AaAa
Slate 502.04:1AaAa
Slate 1001.94:1AaAa
Slate 2001.73:1AaAa
Slate 3001.43:1AaAa
Slate 4001.20:1AaAa
Slate 5002.23:1AaAa
Slate 6003.56:1AaAa
Slate 7004.86:1AaAa
Slate 8006.87:1AaAa
Slate 9008.38:1AaAa
Black9.86:1AaAa
Colour vision deficiency
true color
protanopia · #A5BBF1
deuteranopia · #8DAAEE
tritanopia · #00CDCF

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. #37bfef 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.

#F2FAFC
#E5F5FA
#C5EAF7
#97DEF7
#63CDF3
#37bfef
#12ACE3
#0F8FBD
#0C7397
#0D546D
#083544
Base = 500Lightest = 50 · #F2FAFCDarkest = 950 · #083544Text 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 0.033 226.9);
  --brand-100: oklch(0.94 0.052 226.9);
  --brand-200: oklch(0.88 0.079 226.9);
  --brand-300: oklch(0.80 0.102 226.9);
  --brand-400: oklch(0.72 0.121 226.9);
  --brand-500: oklch(0.64 0.131 226.9);
  --brand-600: oklch(0.56 0.131 226.9);
  --brand-700: oklch(0.48 0.123 226.9);
  --brand-800: oklch(0.40 0.110 226.9);
  --brand-900: oklch(0.32 0.092 226.9);
  --brand-950: oklch(0.24 0.072 226.9);
}

Colors that work with #37bfef

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#F4F9FA
Tinted page background
Border#C0E1ED
Hairlines and dividers
Muted text#4B869B
Captions on the surface
Accent#F33532
Second voice, not a rival
Dark variant#095A76
Hover, pressed, headers
Light variant#E7F7FD
Selected rows, tints
Dark surface#142024
Dark-mode background
Hover#16B4EC
One step down in lightness
Pressed#109CCE
Two steps down
Disabled#C0D0D6
Chroma pulled out
Focus ring#40CAFA
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 #37bfef

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 #095A76
Safe as a 1px border on white
No — use #11A0D3

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.

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

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

Reads as
  • FormalityLow
  • EnergyHigh
  • Weight42/100
  • 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#EF6737
Analogous left#37EFC3
Analogous right#3763EF
Split-complement 1#EF3763
Split-complement 2#EFC337
Triadic 1#EF37BF
Triadic 2#BFEF37
Tetradic#C337EF
On the wheel
Base+30°−30°+120°+240°+180°196°

#37bfef sits at 196°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red21.6%
Green74.9%
Blue93.7%
R · 0–255
55
0x37
G · 0–255
191
0xbf
B · 0–255
239
0xef

CMYK percentages

Cyan77.0%
Magenta20.1%
Yellow0.0%
Key (black)6.3%

Total ink coverage is 103%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#37bfef text on a black background

contrast 9.86:1

Card sample

#37bfef text on a white background

contrast 2.13:1

Card sample

#37bfef on grey

1.94:1

#37bfef on its own surface

2.01:1

#37bfef on its dark surface

7.82:1

CSS3 live lab

Text font color

The quick brown fox

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

Glowing headline

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

Soft neon halo

text-shadow: 0 0 14px rgba(55, 191, 239, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(55, 191, 239, 0.45);
Border & gradient
Gradient panel
border: 3px solid #37bfef;
background: linear-gradient(135deg, #37bfef, #3744EF);
Gradient text

Gradient headline

background: linear-gradient(90deg, #37bfef, #5837EF);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #37bfef;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #37bfef;
caret-color: #37bfef;
Left rule
Pull quote or callout
border-left: 4px solid #37bfef;
Ring + tint
Selected chip
background: #E7F7FD;
box-shadow: inset 0 0 0 2px #37bfef;
Conic badge
68%
background: conic-gradient(#37bfef 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #37bfef 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, 191, 239, 0.5)
rgb(55 191 239 / 50%)
#37bfef80
hsl(196 85% 58% / 50%)
color-mix(in srgb, #37bfef 50%, transparent)
Alpha8-digit hexFlat on white
10%#37bfef1a#EBF9FD
20%#37bfef33#D7F2FC
40%#37bfef66#AFE5F9
60%#37bfef99#87D9F5
80%#37bfefcc#5FCCF2

Gradients from #37bfef

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, #6FD1F4, #37bfef 45%, #095A76);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #37bfef, #1D1AED);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #37bfef, #EF6737);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #8CDAF6 0%, #37bfef 45%, #095A76 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4F9FA, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #66F3C5 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #536CF1 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #095A76 0%, transparent 65%), #37bfef;

Monochromatic scale

Palettes built from #37bfef

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.

#37bfef 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

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 9.86:1.

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.

#37bfef, answered

What color is #37bfef?

#37bfef is a balanced electric cyan, closest to Deep Sky Blue (ΔE2000 3.4). It sits at 196° on the hue wheel with 85% saturation and 58% lightness, which reads as cool.

What is the RGB value of #37bfef?

rgb(55, 191, 239) — 55 red, 191 green and 239 blue out of 255, or 21.6% / 74.9% / 93.7% by channel.

What is #37bfef in HSL and HSV?

hsl(196, 85%, 58%) and hsv(196, 77%, 94%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #37bfef a light or a dark color?

It is a mid-tone. Relative luminance is 0.4431 and perceived brightness is 67%, so black text on it reaches 9.86:1.

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

Black. It scores 9.86:1 against #37bfef, versus 2.13:1 for white — AAA at any size.

Is #37bfef accessible on a white background?

#37bfef on white scores 2.13:1, which fails WCAG AA at every size. Darken it to #0D80A8 to reach 4.5:1, or #0A5F7E for 7:1.

What is the complementary color of #37bfef?

#EF6737 sits directly opposite on the wheel. Softer options are the split-complements #EF3763 and #EFC337, which give the same contrast with far less vibration.

What colors go well with #37bfef?

For interface work: #F4F9FA as the surface, #C0E1ED for borders, #4B869B for secondary text, #F33532 as an accent and #095A76 for hover and pressed states. For a palette, the analogous pair #37EFC3 and #3763EF stays calm, while #EF6737 is the loudest partner.

What is #37bfef in CMYK for printing?

cmyk(77%, 20%, 0%, 6%). 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 #37bfef warm or cool?

Cool — it scores 94 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #37EFDC; nudged cooler, #35A6F1.

Which Tailwind color is closest to #37bfef?

The cyan family — its 500 step is #06b6d4, ΔE2000 6.6 away. That is a visible difference, so define #37bfef as a custom token rather than reaching for the built-in.

How do I use #37bfef in Tailwind CSS?

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

rgba(55, 191, 239, 0.5), or #37bfef80 in eight-digit hex. Over white that composites to #9BDFF7; over black, #1C6078.

Is #37bfef a web-safe color?

No. The nearest web-safe colour is #33CCFF, ΔE2000 3.3 away. The palette only matters for legacy displays and some email clients now.

What does the color #37bfef 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 #37bfef?

The safest is same-hue elevation: linear-gradient(135deg, #6FD1F4, #37bfef 45%, #095A76). For more colour, a short hue run to #1D1AED keeps it rich without turning muddy.

Work with #37bfef in the Color Lab

Every tool opens with this colour already loaded.

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