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cyan · cool

#42ecdf

a balanced, electric cyan · cool · closest name: Turquoise

Token name suggestion: Atlas Lagoon

RGB
66, 236, 223
HSL
175°, 82%, 59%
CMYK
72, 0, 6, 8
Luminance
0.6648

#42ecdf is a balanced electric cyan, 175° on the wheel and 86/100 on the cool side. Put black text on it (14.30:1). As text it scores 1.47:1 on white — use #0D837A instead. Nearest name is Turquoise, nearest Tailwind family is teal.

hsl(175 82% 59%)rgb(66 236 223)Base step 500AAA inkCool

At a glance

Every number on this page in one read: what #42ecdf is made of, how bright it looks, and which way it leans.

Hex
#42ecdf
Hue
175°
cyan
Saturation
82%
electric
Lightness
59%
balanced
Brightness
93%
HSV value
Perceived
78%
weighted brightness
Luminance
0.6648
WCAG relative
Temperature
Cool
86/100 cool
Color family
Cyan
Tone
Electric
Best ink
Black
14.30:1
Closest name
Turquoise
ΔE2000 2.9
Chroma
45.5
LCH, 0–130ish
OKLCH L
0.856
perceptual lightness
Tailwind
teal
500 · ΔE 13.1
Web-safe
#33FFCC
nearest of 216
Where it sits
Hue175° of 360°
Saturation82%
Lightness59%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #42ecdf.

Temperature
Warm ← → Cool86% 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%
Green90%
Blue8%

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

Every format

HEX#42ecdf
HEX (8-digit)#42ecdfff
RGBrgb(66, 236, 223)
RGBArgba(66, 236, 223, 1)
HSLhsl(175, 82%, 59%)
HSV / HSBhsv(175, 72%, 93%)
HWBhwb(175 26% 7%)
CMYKcmyk(72%, 0%, 6%, 8%)
LABlab(85.2 -45.1 -6.1)
LCHlch(85.2 45.5 187.7)
OKLCHoklch(0.856 0.136 187.3)
XYZ (D65)xyz(45.56, 66.47, 80.23)
Decimal4386015
Display P3color(display-p3 0.259 0.925 0.875)
Web-safe#33FFCC

Copy-ready code

every platformclick to select
/* CSS */
color: #42ecdf;
background-color: #42ecdf;
/* CSS custom property */
--brand: #42ecdf;
/* Tailwind (arbitrary) */
class="text-[#42ecdf] bg-[#42ecdf]"
/* SCSS */
$brand: #42ecdf;
/* SwiftUI */
Color(red: 0.259, green: 0.925, blue: 0.875)
/* UIKit */
UIColor(red: 0.259, green: 0.925, blue: 0.875, alpha: 1)
/* Android XML */
<color name="brand">#42ECDF</color>
/* Android Compose */
Color(0xFF42ECDF)
/* Flutter */
Color(0xFF42ECDF)
/* Python / OpenCV (BGR) */
(223, 236, 66)
/* Python / PIL (RGB) */
(66, 236, 223)
/* Java AWT */
new Color(66, 236, 223)
/* .NET */
Color.FromArgb(255, 66, 236, 223)
/* OpenGL / Unity (0–1) */
(0.2588f, 0.9255f, 0.8745f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{66,236,223}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #42ecdf 85%, white);
border-color: color-mix(in oklab, #42ecdf 40%, transparent);
/* theme-aware in one line */
color: light-dark(#0C746C, #D3EEEC);
/* relative colour syntax */
--hover: hsl(from #42ecdf 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: #F2FCFB;
  --brand-100: #E6F9F8;
  --brand-200: #C6F6F2;
  --brand-300: #99F5EE;
  --brand-400: #66F0E5;
  --brand-500: #42ecdf;
  --brand-600: #16DECF;
  --brand-700: #13B9AD;
  --brand-800: #0F948A;
  --brand-900: #0F6B64;
  --brand-950: #09433F;
  --brand: #42ecdf;
  --brand-ink: #000000;
  --brand-surface: #F4FAFA;
  --brand-border: #C0EDE9;
  --brand-hover: #22E9D9;
  --brand-pressed: #15D1C3;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142423;
    --brand-ink: #D3EEEC;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F2FCFB',
        100: '#E6F9F8',
        200: '#C6F6F2',
        300: '#99F5EE',
        400: '#66F0E5',
        500: '#42ecdf',
        600: '#16DECF',
        700: '#13B9AD',
        800: '#0F948A',
        900: '#0F6B64',
        950: '#09433F',
        DEFAULT: '#42ecdf',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F2FCFB,
  '100': #E6F9F8,
  '200': #C6F6F2,
  '300': #99F5EE,
  '400': #66F0E5,
  '500': #42ecdf,
  '600': #16DECF,
  '700': #13B9AD,
  '800': #0F948A,
  '900': #0F6B64,
  '950': #09433F,
);
$brand-base: #42ecdf;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F2FCFB", "$type": "color" },
      "100": { "$value": "#E6F9F8", "$type": "color" },
      "200": { "$value": "#C6F6F2", "$type": "color" },
      "300": { "$value": "#99F5EE", "$type": "color" },
      "400": { "$value": "#66F0E5", "$type": "color" },
      "500": { "$value": "#42ecdf", "$type": "color" },
      "600": { "$value": "#16DECF", "$type": "color" },
      "700": { "$value": "#13B9AD", "$type": "color" },
      "800": { "$value": "#0F948A", "$type": "color" },
      "900": { "$value": "#0F6B64", "$type": "color" },
      "950": { "$value": "#09433F", "$type": "color" }
    },
    "brandInk": { "$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 #42ecdf · 14.30:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.47:1
AA fail · AA large fail · AAA fail
Aa
Black text · 14.30:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #42ecdf as text scores 1.47:1 on white and 14.30:1 on black.
Best tinted ink on it, if plain black or white feels flat: #0C746C at 3.83:1.

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
#0D837A · 4.62:1
AA on white−31% L
#0D837A
The quick fox
#0A625B · 7.21:1
AAA on white−38% L
#0A625B
The quick fox
#42ecdf · 14.30:1
AA on blackalready passes
#42ecdf
The quick fox
#42ecdf · 14.30:1
AAA on blackalready passes
#42ecdf

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #10A398 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
#42ecdf on white: 1.47:1
AA ✗ fail · AA-large · AAA
Aa
#42ecdf on black: 14.30:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #42ecdf as text on that neutral, and that neutral as text on #42ecdf.

NeutralRatioBoth directions
White1.47:1AaAa
Slate 501.40:1AaAa
Slate 1001.34:1AaAa
Slate 2001.19:1AaAa
Slate 3001.01:1AaAa
Slate 4001.75:1AaAa
Slate 5003.24:1AaAa
Slate 6005.16:1AaAa
Slate 7007.05:1AaAa
Slate 8009.96:1AaAa
Slate 90012.15:1AaAa
Black14.30:1AaAa
Colour vision deficiency
true color
protanopia · #DFDFDF
deuteranopia · #C7CEE1
tritanopia · #00F2E8

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. #42ecdf 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.

#F2FCFB
#E6F9F8
#C6F6F2
#99F5EE
#66F0E5
#42ecdf
#16DECF
#13B9AD
#0F948A
#0F6B64
#09433F
Base = 500Lightest = 50 · #F2FCFBDarkest = 950 · #09433FText 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 0.034 187.3);
  --brand-100: oklch(0.94 0.054 187.3);
  --brand-200: oklch(0.88 0.081 187.3);
  --brand-300: oklch(0.80 0.106 187.3);
  --brand-400: oklch(0.72 0.125 187.3);
  --brand-500: oklch(0.64 0.136 187.3);
  --brand-600: oklch(0.56 0.136 187.3);
  --brand-700: oklch(0.48 0.127 187.3);
  --brand-800: oklch(0.40 0.114 187.3);
  --brand-900: oklch(0.32 0.095 187.3);
  --brand-950: oklch(0.24 0.075 187.3);
}

Colors that work with #42ecdf

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#C0EDE9
Hairlines and dividers
Muted text#4B9B95
Captions on the surface
Accent#F03E78
Second voice, not a rival
Dark variant#0C746C
Hover, pressed, headers
Light variant#E8FDFB
Selected rows, tints
Dark surface#142423
Dark-mode background
Hover#22E9D9
One step down in lightness
Pressed#15D1C3
Two steps down
Disabled#C5DAD8
Chroma pulled out
Focus ring#4BF7EA
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 #42ecdf

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 #0C746C
Safe as a 1px border on white
No — use #10A398

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
  • Weight41/100
  • 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#EC424F
Analogous left#42EC8A
Analogous right#42A4EC
Split-complement 1#EC42A4
Split-complement 2#EC8A42
Triadic 1#DF42EC
Triadic 2#ECDF42
Tetradic#8A42EC
On the wheel
Base+30°−30°+120°+240°+180°175°

#42ecdf sits at 175°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red25.9%
Green92.5%
Blue87.5%
R · 0–255
66
0x42
G · 0–255
236
0xec
B · 0–255
223
0xdf

CMYK percentages

Cyan72.0%
Magenta0.0%
Yellow5.5%
Key (black)7.5%

Total ink coverage is 85%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#42ecdf text on a black background

contrast 14.30:1

Card sample

#42ecdf text on a white background

contrast 1.47:1

Card sample

#42ecdf on grey

1.34:1

#42ecdf on its own surface

1.39:1

#42ecdf on its dark surface

10.94:1

CSS3 live lab

Text font color

The quick brown fox

color: #42ecdf;
Background color
Panel with #42ecdf background
background-color: #42ecdf;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #42ecdf;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(66, 236, 223, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(66, 236, 223, 0.45);
Border & gradient
Gradient panel
border: 3px solid #42ecdf;
background: linear-gradient(135deg, #42ecdf, #4288EC);
Gradient text

Gradient headline

background: linear-gradient(90deg, #42ecdf, #425DEC);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #42ecdf;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #42ecdf;
caret-color: #42ecdf;
Left rule
Pull quote or callout
border-left: 4px solid #42ecdf;
Ring + tint
Selected chip
background: #E8FDFB;
box-shadow: inset 0 0 0 2px #42ecdf;
Conic badge
68%
background: conic-gradient(#42ecdf 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #42ecdf 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(66, 236, 223, 0.5)
rgb(66 236 223 / 50%)
#42ecdf80
hsl(175 82% 59% / 50%)
color-mix(in srgb, #42ecdf 50%, transparent)
Alpha8-digit hexFlat on white
10%#42ecdf1a#ECFDFC
20%#42ecdf33#D9FBF9
40%#42ecdf66#B3F7F2
60%#42ecdf99#8EF4EC
80%#42ecdfcc#68F0E5

Gradients from #42ecdf

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, #7AF2E8, #42ecdf 45%, #0C746C);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #42ecdf, #2666E9);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #42ecdf, #EC424F);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #95F4ED 0%, #42ecdf 45%, #0C746C 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%, #70F19C 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #5EA5EF 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #0C746C 0%, transparent 65%), #42ecdf;

Monochromatic scale

Palettes built from #42ecdf

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.

#42ecdf 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 14.30:1.

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.

#42ecdf, answered

What color is #42ecdf?

#42ecdf is a balanced electric cyan, closest to Turquoise (ΔE2000 2.9). It sits at 175° on the hue wheel with 82% saturation and 59% lightness, which reads as cool.

What is the RGB value of #42ecdf?

rgb(66, 236, 223) — 66 red, 236 green and 223 blue out of 255, or 25.9% / 92.5% / 87.5% by channel.

What is #42ecdf in HSL and HSV?

hsl(175, 82%, 59%) and hsv(175, 72%, 93%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #42ecdf a light or a dark color?

It is a light color. Relative luminance is 0.6648 and perceived brightness is 78%, so black text on it reaches 14.30:1.

Should I use black or white text on #42ecdf?

Black. It scores 14.30:1 against #42ecdf, versus 1.47:1 for white — AAA at any size.

Is #42ecdf accessible on a white background?

#42ecdf on white scores 1.47:1, which fails WCAG AA at every size. Darken it to #0D837A to reach 4.5:1, or #0A625B for 7:1.

What is the complementary color of #42ecdf?

#EC424F sits directly opposite on the wheel. Softer options are the split-complements #EC42A4 and #EC8A42, which give the same contrast with far less vibration.

What colors go well with #42ecdf?

For interface work: #F4FAFA as the surface, #C0EDE9 for borders, #4B9B95 for secondary text, #F03E78 as an accent and #0C746C for hover and pressed states. For a palette, the analogous pair #42EC8A and #42A4EC stays calm, while #EC424F is the loudest partner.

What is #42ecdf in CMYK for printing?

cmyk(72%, 0%, 6%, 8%). 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 #42ecdf warm or cool?

Cool — it scores 86 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #42ECA1; nudged cooler, #40C2EE.

Which Tailwind color is closest to #42ecdf?

The teal family — its 500 step is #14b8a6, ΔE2000 13.1 away. That is a visible difference, so define #42ecdf as a custom token rather than reaching for the built-in.

How do I use #42ecdf in Tailwind CSS?

Inline it as an arbitrary value with bg-[#42ecdf] or text-[#42ecdf], 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 #42ecdf with 50% opacity?

rgba(66, 236, 223, 0.5), or #42ecdf80 in eight-digit hex. Over white that composites to #A1F6EF; over black, #217670.

Is #42ecdf a web-safe color?

No. The nearest web-safe colour is #33FFCC, ΔE2000 10.7 away. The palette only matters for legacy displays and some email clients now.

What does the color #42ecdf 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 #42ecdf?

The safest is same-hue elevation: linear-gradient(135deg, #7AF2E8, #42ecdf 45%, #0C746C). For more colour, a short hue run to #2666E9 keeps it rich without turning muddy.

Work with #42ecdf in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #42ecdf at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.