Skip to content
cyan · cool

#42dfdf

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

Token name suggestion: Atlas Teal

RGB
66, 223, 223
HSL
180°, 71%, 57%
CMYK
70, 0, 0, 13
Luminance
0.5926

#42dfdf is a balanced vivid cyan, 180° on the wheel and 88/100 on the cool side. Put black text on it (12.85:1). As text it scores 1.63:1 on white — use #168282 instead. Nearest name is Medium Turquoise, nearest Tailwind family is teal.

hsl(180 71% 57%)rgb(66 223 223)Base step 500AAA inkCool

At a glance

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

Hex
#42dfdf
Hue
180°
cyan
Saturation
71%
vivid
Lightness
57%
balanced
Brightness
87%
HSV value
Perceived
75%
weighted brightness
Luminance
0.5926
WCAG relative
Temperature
Cool
88/100 cool
Color family
Cyan
Tone
Vivid
Best ink
Black
12.85:1
Closest name
Medium Turquoise
ΔE2000 3.8
Chroma
41.0
LCH, 0–130ish
OKLCH L
0.825
perceptual lightness
Tailwind
teal
500 · ΔE 12.2
Web-safe
#33CCCC
nearest of 216
Where it sits
Hue180° of 360°
Saturation71%
Lightness57%
Saturation × lightness field

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

Temperature
Warm ← → Cool88% 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%
Green89%
Blue9%

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

Every format

HEX#42dfdf
HEX (8-digit)#42dfdfff
RGBrgb(66, 223, 223)
RGBArgba(66, 223, 223, 1)
HSLhsl(180, 71%, 57%)
HSV / HSBhsv(180, 70%, 87%)
HWBhwb(180 26% 13%)
CMYKcmyk(70%, 0%, 0%, 13%)
LABlab(81.4 -39.3 -11.8)
LCHlch(81.4 41.0 196.6)
OKLCHoklch(0.825 0.126 195.0)
XYZ (D65)xyz(41.95, 59.26, 79.02)
Decimal4382687
Display P3color(display-p3 0.259 0.875 0.875)
Web-safe#33CCCC

Copy-ready code

every platformclick to select
/* CSS */
color: #42dfdf;
background-color: #42dfdf;
/* CSS custom property */
--brand: #42dfdf;
/* Tailwind (arbitrary) */
class="text-[#42dfdf] bg-[#42dfdf]"
/* SCSS */
$brand: #42dfdf;
/* SwiftUI */
Color(red: 0.259, green: 0.875, blue: 0.875)
/* UIKit */
UIColor(red: 0.259, green: 0.875, blue: 0.875, alpha: 1)
/* Android XML */
<color name="brand">#42DFDF</color>
/* Android Compose */
Color(0xFF42DFDF)
/* Flutter */
Color(0xFF42DFDF)
/* Python / OpenCV (BGR) */
(223, 223, 66)
/* Python / PIL (RGB) */
(66, 223, 223)
/* Java AWT */
new Color(66, 223, 223)
/* .NET */
Color.FromArgb(255, 66, 223, 223)
/* OpenGL / Unity (0–1) */
(0.2588f, 0.8745f, 0.8745f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{66,223,223}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #42dfdf 85%, white);
border-color: color-mix(in oklab, #42dfdf 40%, transparent);
/* theme-aware in one line */
color: light-dark(#126D6D, #D3EEEE);
/* relative colour syntax */
--hover: hsl(from #42dfdf 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: #E7F8F8;
  --brand-200: #C9F3F3;
  --brand-300: #9FEFEF;
  --brand-400: #6FE7E7;
  --brand-500: #42dfdf;
  --brand-600: #23D1D1;
  --brand-700: #1EAEAE;
  --brand-800: #188C8C;
  --brand-900: #156565;
  --brand-950: #0D3F3F;
  --brand: #42dfdf;
  --brand-ink: #000000;
  --brand-surface: #F4FAFA;
  --brand-border: #C0EDED;
  --brand-hover: #25D9D9;
  --brand-pressed: #20BABA;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142424;
    --brand-ink: #D3EEEE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F3FCFC',
        100: '#E7F8F8',
        200: '#C9F3F3',
        300: '#9FEFEF',
        400: '#6FE7E7',
        500: '#42dfdf',
        600: '#23D1D1',
        700: '#1EAEAE',
        800: '#188C8C',
        900: '#156565',
        950: '#0D3F3F',
        DEFAULT: '#42dfdf',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F3FCFC,
  '100': #E7F8F8,
  '200': #C9F3F3,
  '300': #9FEFEF,
  '400': #6FE7E7,
  '500': #42dfdf,
  '600': #23D1D1,
  '700': #1EAEAE,
  '800': #188C8C,
  '900': #156565,
  '950': #0D3F3F,
);
$brand-base: #42dfdf;
$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": "#E7F8F8", "$type": "color" },
      "200": { "$value": "#C9F3F3", "$type": "color" },
      "300": { "$value": "#9FEFEF", "$type": "color" },
      "400": { "$value": "#6FE7E7", "$type": "color" },
      "500": { "$value": "#42dfdf", "$type": "color" },
      "600": { "$value": "#23D1D1", "$type": "color" },
      "700": { "$value": "#1EAEAE", "$type": "color" },
      "800": { "$value": "#188C8C", "$type": "color" },
      "900": { "$value": "#156565", "$type": "color" },
      "950": { "$value": "#0D3F3F", "$type": "color" }
    },
    "brandInk": { "$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 #42dfdf · 12.85:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.63:1
AA fail · AA large fail · AAA fail
Aa
Black text · 12.85:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #42dfdf as text scores 1.63:1 on white and 12.85:1 on black.
Best tinted ink on it, if plain black or white feels flat: #126D6D at 3.74:1.

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
#168282 · 4.62:1
AA on white−27% L
#168282
The quick fox
#116363 · 7.03:1
AAA on white−34% L
#116363
The quick fox
#42dfdf · 12.85:1
AA on blackalready passes
#42dfdf
The quick fox
#42dfdf · 12.85:1
AAA on blackalready passes
#42dfdf

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #1CA4A4 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
#42dfdf on white: 1.63:1
AA ✗ fail · AA-large · AAA
Aa
#42dfdf on black: 12.85:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

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

NeutralRatioBoth directions
White1.63:1AaAa
Slate 501.56:1AaAa
Slate 1001.49:1AaAa
Slate 2001.33:1AaAa
Slate 3001.10:1AaAa
Slate 4001.57:1AaAa
Slate 5002.91:1AaAa
Slate 6004.64:1AaAa
Slate 7006.34:1AaAa
Slate 8008.95:1AaAa
Slate 90010.93:1AaAa
Black12.85:1AaAa
Colour vision deficiency
true color
protanopia · #D0D4DF
deuteranopia · #B9C3E0
tritanopia · #00E6DF

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. #42dfdf 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
#E7F8F8
#C9F3F3
#9FEFEF
#6FE7E7
#42dfdf
#23D1D1
#1EAEAE
#188C8C
#156565
#0D3F3F
Base = 500Lightest = 50 · #F3FCFCDarkest = 950 · #0D3F3FText 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 0.032 195.0);
  --brand-100: oklch(0.94 0.051 195.0);
  --brand-200: oklch(0.88 0.076 195.0);
  --brand-300: oklch(0.80 0.099 195.0);
  --brand-400: oklch(0.72 0.116 195.0);
  --brand-500: oklch(0.64 0.126 195.0);
  --brand-600: oklch(0.56 0.126 195.0);
  --brand-700: oklch(0.48 0.119 195.0);
  --brand-800: oklch(0.40 0.106 195.0);
  --brand-900: oklch(0.32 0.088 195.0);
  --brand-950: oklch(0.24 0.069 195.0);
}

Colors that work with #42dfdf

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#C0EDED
Hairlines and dividers
Muted text#4B9B9B
Captions on the surface
Accent#E33E67
Second voice, not a rival
Dark variant#126D6D
Hover, pressed, headers
Light variant#E9FBFB
Selected rows, tints
Dark surface#142424
Dark-mode background
Hover#25D9D9
One step down in lightness
Pressed#20BABA
Two steps down
Disabled#BDD5D5
Chroma pulled out
Focus ring#4AECEC
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 #42dfdf

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 #126D6D
Safe as a 1px border on white
No — use #1CA4A4

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
  • Weight43/100
  • 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#DF4242
Analogous left#42DF91
Analogous right#4291DF
Split-complement 1#DF4291
Split-complement 2#DF9142
Triadic 1#DF42DF
Triadic 2#DFDF42
Tetradic#9142DF
On the wheel
Base+30°−30°+120°+240°+180°180°

#42dfdf sits at 180°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red25.9%
Green87.5%
Blue87.5%
R · 0–255
66
0x42
G · 0–255
223
0xdf
B · 0–255
223
0xdf

CMYK percentages

Cyan70.4%
Magenta0.0%
Yellow0.0%
Key (black)12.5%

Total ink coverage is 83%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#42dfdf text on a black background

contrast 12.85:1

Card sample

#42dfdf text on a white background

contrast 1.63:1

Card sample

#42dfdf on grey

1.49:1

#42dfdf on its own surface

1.55:1

#42dfdf on its dark surface

9.83:1

CSS3 live lab

Text font color

The quick brown fox

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

Glowing headline

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

Soft neon halo

text-shadow: 0 0 14px rgba(66, 223, 223, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(66, 223, 223, 0.45);
Border & gradient
Gradient panel
border: 3px solid #42dfdf;
background: linear-gradient(135deg, #42dfdf, #4276DF);
Gradient text

Gradient headline

background: linear-gradient(90deg, #42dfdf, #424FDF);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #42dfdf;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #42dfdf;
caret-color: #42dfdf;
Left rule
Pull quote or callout
border-left: 4px solid #42dfdf;
Ring + tint
Selected chip
background: #E9FBFB;
box-shadow: inset 0 0 0 2px #42dfdf;
Conic badge
68%
background: conic-gradient(#42dfdf 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #42dfdf 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, 223, 223, 0.5)
rgb(66 223 223 / 50%)
#42dfdf80
hsl(180 71% 57% / 50%)
color-mix(in srgb, #42dfdf 50%, transparent)
Alpha8-digit hexFlat on white
10%#42dfdf1a#ECFCFC
20%#42dfdf33#D9F9F9
40%#42dfdf66#B3F2F2
60%#42dfdf99#8EECEC
80%#42dfdfcc#68E5E5

Gradients from #42dfdf

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, #77E8E8, #42dfdf 45%, #126D6D);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #42dfdf, #2855DB);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #42dfdf, #DF4242);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #91ECEC 0%, #42dfdf 45%, #126D6D 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%, #6EE6A0 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #5C95E3 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #126D6D 0%, transparent 65%), #42dfdf;

Monochromatic scale

Palettes built from #42dfdf

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.

#42dfdf 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 12.85:1.

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.

#42dfdf, answered

What color is #42dfdf?

#42dfdf is a balanced vivid cyan, closest to Medium Turquoise (ΔE2000 3.8). It sits at 180° on the hue wheel with 71% saturation and 57% lightness, which reads as cool.

What is the RGB value of #42dfdf?

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

What is #42dfdf in HSL and HSV?

hsl(180, 71%, 57%) and hsv(180, 70%, 87%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #42dfdf a light or a dark color?

It is a light color. Relative luminance is 0.5926 and perceived brightness is 75%, so black text on it reaches 12.85:1.

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

Black. It scores 12.85:1 against #42dfdf, versus 1.63:1 for white — AAA at any size.

Is #42dfdf accessible on a white background?

#42dfdf on white scores 1.63:1, which fails WCAG AA at every size. Darken it to #168282 to reach 4.5:1, or #116363 for 7:1.

What is the complementary color of #42dfdf?

#DF4242 sits directly opposite on the wheel. Softer options are the split-complements #DF4291 and #DF9142, which give the same contrast with far less vibration.

What colors go well with #42dfdf?

For interface work: #F4FAFA as the surface, #C0EDED for borders, #4B9B9B for secondary text, #E33E67 as an accent and #126D6D for hover and pressed states. For a palette, the analogous pair #42DF91 and #4291DF stays calm, while #DF4242 is the loudest partner.

What is #42dfdf in CMYK for printing?

cmyk(70%, 0%, 0%, 13%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #42dfdf warm or cool?

Cool — it scores 88 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #42DFA5; nudged cooler, #40B2E1.

Which Tailwind color is closest to #42dfdf?

The teal family — its 500 step is #14b8a6, ΔE2000 12.2 away. That is a visible difference, so define #42dfdf as a custom token rather than reaching for the built-in.

How do I use #42dfdf in Tailwind CSS?

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

rgba(66, 223, 223, 0.5), or #42dfdf80 in eight-digit hex. Over white that composites to #A1EFEF; over black, #217070.

Is #42dfdf a web-safe color?

No. The nearest web-safe colour is #33CCCC, ΔE2000 4.6 away. The palette only matters for legacy displays and some email clients now.

What does the color #42dfdf 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 #42dfdf?

The safest is same-hue elevation: linear-gradient(135deg, #77E8E8, #42dfdf 45%, #126D6D). For more colour, a short hue run to #2855DB keeps it rich without turning muddy.

Work with #42dfdf in the Color Lab

Every tool opens with this colour already loaded.

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