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cyan · cool

#28ada8

a dark, vivid cyan · cool · closest name: Light Sea Green

Token name suggestion: Dusk Glacier

RGB
40, 173, 168
HSL
178°, 62%, 42%
CMYK
77, 0, 3, 32
Luminance
0.3317

#28ada8 is a dark vivid cyan, 178° on the wheel and 87/100 on the cool side. Put black text on it (7.63:1). As text it scores 2.75:1 on white — use #1E8480 instead. Nearest name is Light Sea Green, nearest Tailwind family is teal.

hsl(178 62% 42%)rgb(40 173 168)Base step 700AAA inkCool

At a glance

Every number on this page in one read: what #28ada8 is made of, how bright it looks, and which way it leans.

Hex
#28ada8
Hue
178°
cyan
Saturation
62%
vivid
Lightness
42%
dark
Brightness
68%
HSV value
Perceived
57%
weighted brightness
Luminance
0.3317
WCAG relative
Temperature
Cool
87/100 cool
Color family
Cyan
Tone
Vivid
Best ink
Black
7.63:1
Closest name
Light Sea Green
ΔE2000 1.8
Chroma
35.8
LCH, 0–130ish
OKLCH L
0.679
perceptual lightness
Tailwind
teal
500 · ΔE 5.4
Web-safe
#339999
nearest of 216
Where it sits
Hue178° of 360°
Saturation62%
Lightness42%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #28ada8.

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#28ada8
HEX (8-digit)#28ada8ff
RGBrgb(40, 173, 168)
RGBArgba(40, 173, 168, 1)
HSLhsl(178, 62%, 42%)
HSV / HSBhsv(178, 77%, 68%)
HWBhwb(178 16% 32%)
CMYKcmyk(77%, 0%, 3%, 32%)
LABlab(64.3 -35.0 -7.4)
LCHlch(64.3 35.8 192.0)
OKLCHoklch(0.679 0.108 191.0)
XYZ (D65)xyz(22.88, 33.16, 42.23)
Decimal2665896
Display P3color(display-p3 0.157 0.678 0.659)
Web-safe#339999

Copy-ready code

every platformclick to select
/* CSS */
color: #28ada8;
background-color: #28ada8;
/* CSS custom property */
--brand: #28ada8;
/* Tailwind (arbitrary) */
class="text-[#28ada8] bg-[#28ada8]"
/* SCSS */
$brand: #28ada8;
/* SwiftUI */
Color(red: 0.157, green: 0.678, blue: 0.659)
/* UIKit */
UIColor(red: 0.157, green: 0.678, blue: 0.659, alpha: 1)
/* Android XML */
<color name="brand">#28ADA8</color>
/* Android Compose */
Color(0xFF28ADA8)
/* Flutter */
Color(0xFF28ADA8)
/* Python / OpenCV (BGR) */
(168, 173, 40)
/* Python / PIL (RGB) */
(40, 173, 168)
/* Java AWT */
new Color(40, 173, 168)
/* .NET */
Color.FromArgb(255, 40, 173, 168)
/* OpenGL / Unity (0–1) */
(0.1569f, 0.6784f, 0.6588f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{40,173,168}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #28ada8 85%, white);
border-color: color-mix(in oklab, #28ada8 40%, transparent);
/* theme-aware in one line */
color: light-dark(#186864, #D3EEED);
/* relative colour syntax */
--hover: hsl(from #28ada8 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: #F4FBFB;
  --brand-100: #E8F7F7;
  --brand-200: #CCF0EF;
  --brand-300: #A4EAE7;
  --brand-400: #76DFDB;
  --brand-500: #49D5CF;
  --brand-600: #2EC7C1;
  --brand-700: #28ada8;
  --brand-800: #1F8581;
  --brand-900: #1A605E;
  --brand-950: #103C3B;
  --brand: #28ada8;
  --brand-ink: #000000;
  --brand-surface: #F4FAFA;
  --brand-border: #C0EDEB;
  --brand-hover: #21908C;
  --brand-pressed: #1B7370;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142424;
    --brand-ink: #D3EEED;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F4FBFB',
        100: '#E8F7F7',
        200: '#CCF0EF',
        300: '#A4EAE7',
        400: '#76DFDB',
        500: '#49D5CF',
        600: '#2EC7C1',
        700: '#28ada8',
        800: '#1F8581',
        900: '#1A605E',
        950: '#103C3B',
        DEFAULT: '#28ada8',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F4FBFB,
  '100': #E8F7F7,
  '200': #CCF0EF,
  '300': #A4EAE7,
  '400': #76DFDB,
  '500': #49D5CF,
  '600': #2EC7C1,
  '700': #28ada8,
  '800': #1F8581,
  '900': #1A605E,
  '950': #103C3B,
);
$brand-base: #28ada8;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F4FBFB", "$type": "color" },
      "100": { "$value": "#E8F7F7", "$type": "color" },
      "200": { "$value": "#CCF0EF", "$type": "color" },
      "300": { "$value": "#A4EAE7", "$type": "color" },
      "400": { "$value": "#76DFDB", "$type": "color" },
      "500": { "$value": "#49D5CF", "$type": "color" },
      "600": { "$value": "#2EC7C1", "$type": "color" },
      "700": { "$value": "#28ada8", "$type": "color" },
      "800": { "$value": "#1F8581", "$type": "color" },
      "900": { "$value": "#1A605E", "$type": "color" },
      "950": { "$value": "#103C3B", "$type": "color" }
    },
    "brandInk": { "$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 #28ada8 · 7.63:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 2.75:1
AA fail · AA large fail · AAA fail
Aa
Black text · 7.63:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #28ada8 as text scores 2.75:1 on white and 7.63:1 on black.
Best tinted ink on it, if plain black or white feels flat: #186864 at 2.38:1.

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
#1E8480 · 4.50:1
AA on white−10% L
#1E8480
The quick fox
#176360 · 7.02:1
AAA on white−18% L
#176360
The quick fox
#28ada8 · 7.63:1
AA on blackalready passes
#28ada8
The quick fox
#28ada8 · 7.63:1
AAA on blackalready passes
#28ada8

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #26A5A0 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
#28ada8 on white: 2.75:1
AA ✗ fail · AA-large · AAA
Aa
#28ada8 on black: 7.63:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #28ada8 as text on that neutral, and that neutral as text on #28ada8.

NeutralRatioBoth directions
White2.75:1AaAa
Slate 502.63:1AaAa
Slate 1002.51:1AaAa
Slate 2002.23:1AaAa
Slate 3001.85:1AaAa
Slate 4001.07:1AaAa
Slate 5001.73:1AaAa
Slate 6002.75:1AaAa
Slate 7003.76:1AaAa
Slate 8005.32:1AaAa
Slate 9006.49:1AaAa
Black7.63:1AaAa
Colour vision deficiency
true color
protanopia · #A2A4A8
deuteranopia · #9096A9
tritanopia · #00B2AB

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. #28ada8 is pinned to step 700; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F4FBFB
#E8F7F7
#CCF0EF
#A4EAE7
#76DFDB
#49D5CF
#2EC7C1
#28ada8
#1F8581
#1A605E
#103C3B
Base = 700Lightest = 50 · #F4FBFBDarkest = 950 · #103C3BText 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 0.027 191.0);
  --brand-100: oklch(0.94 0.043 191.0);
  --brand-200: oklch(0.88 0.065 191.0);
  --brand-300: oklch(0.80 0.085 191.0);
  --brand-400: oklch(0.72 0.100 191.0);
  --brand-500: oklch(0.64 0.108 191.0);
  --brand-600: oklch(0.56 0.108 191.0);
  --brand-700: oklch(0.48 0.102 191.0);
  --brand-800: oklch(0.40 0.091 191.0);
  --brand-900: oklch(0.32 0.076 191.0);
  --brand-950: oklch(0.24 0.060 191.0);
}

Colors that work with #28ada8

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#C0EDEB
Hairlines and dividers
Muted text#4B9B98
Captions on the surface
Accent#B1244D
Second voice, not a rival
Dark variant#186864
Hover, pressed, headers
Light variant#EAFAFA
Selected rows, tints
Dark surface#142424
Dark-mode background
Hover#21908C
One step down in lightness
Pressed#1B7370
Two steps down
Disabled#8EB7B5
Chroma pulled out
Focus ring#20C9C3
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 #28ada8

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
  • Headers, footers and dark-mode surfaces
  • Brand accents, badges and data highlights
Use with care
  • Text of any size on white — fails WCAG AA
  • Full-page backgrounds — tiring over long sessions
  • Black text placed on it
  • 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 #186864
Safe as a 1px border on white
No — use #26A5A0

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 low lightness adds weight and formality.

Worth knowing

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

Reads as
  • FormalityHigh
  • EnergyMedium-high
  • Weight58/100
  • 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#AD282D
Analogous left#28AD65
Analogous right#2870AD
Split-complement 1#AD2870
Split-complement 2#AD6528
Triadic 1#A828AD
Triadic 2#ADA828
Tetradic#6528AD
On the wheel
Base+30°−30°+120°+240°+180°178°

#28ada8 sits at 178°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red15.7%
Green67.8%
Blue65.9%
R · 0–255
40
0x28
G · 0–255
173
0xad
B · 0–255
168
0xa8

CMYK percentages

Cyan76.9%
Magenta0.0%
Yellow2.9%
Key (black)32.2%

Total ink coverage is 112%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#28ada8 text on a black background

contrast 7.63:1

Card sample

#28ada8 text on a white background

contrast 2.75:1

Card sample

#28ada8 on grey

2.51:1

#28ada8 on its own surface

2.61:1

#28ada8 on its dark surface

5.84:1

CSS3 live lab

Text font color

The quick brown fox

color: #28ada8;
Background color
Panel with #28ada8 background
background-color: #28ada8;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #28ada8;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(40, 173, 168, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(40, 173, 168, 0.45);
Border & gradient
Gradient panel
border: 3px solid #28ada8;
background: linear-gradient(135deg, #28ada8, #285AAD);
Gradient text

Gradient headline

background: linear-gradient(90deg, #28ada8, #2838AD);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #28ada8;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #28ada8;
caret-color: #28ada8;
Left rule
Pull quote or callout
border-left: 4px solid #28ada8;
Ring + tint
Selected chip
background: #EAFAFA;
box-shadow: inset 0 0 0 2px #28ada8;
Conic badge
68%
background: conic-gradient(#28ada8 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #28ada8 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(40, 173, 168, 0.5)
rgb(40 173 168 / 50%)
#28ada880
hsl(178 62% 42% / 50%)
color-mix(in srgb, #28ada8 50%, transparent)
Alpha8-digit hexFlat on white
10%#28ada81a#EAF7F6
20%#28ada833#D4EFEE
40%#28ada866#A9DEDC
60%#28ada899#7ECECB
80%#28ada8cc#53BDB9

Gradients from #28ada8

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, #40D3CD, #28ada8 45%, #186864);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #28ada8, #224394);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #28ada8, #AD282D);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #59D8D4 0%, #28ada8 45%, #186864 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%, #37D171 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #2E73C6 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #186864 0%, transparent 65%), #28ada8;

Monochromatic scale

Palettes built from #28ada8

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.

#28ada8 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 7.63:1.

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.

#28ada8, answered

What color is #28ada8?

#28ada8 is a dark vivid cyan, closest to Light Sea Green (ΔE2000 1.8). It sits at 178° on the hue wheel with 62% saturation and 42% lightness, which reads as cool.

What is the RGB value of #28ada8?

rgb(40, 173, 168) — 40 red, 173 green and 168 blue out of 255, or 15.7% / 67.8% / 65.9% by channel.

What is #28ada8 in HSL and HSV?

hsl(178, 62%, 42%) and hsv(178, 77%, 68%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #28ada8 a light or a dark color?

It is a mid-tone. Relative luminance is 0.3317 and perceived brightness is 57%, so black text on it reaches 7.63:1.

Should I use black or white text on #28ada8?

Black. It scores 7.63:1 against #28ada8, versus 2.75:1 for white — AAA at any size.

Is #28ada8 accessible on a white background?

#28ada8 on white scores 2.75:1, which fails WCAG AA at every size. Darken it to #1E8480 to reach 4.5:1, or #176360 for 7:1.

What is the complementary color of #28ada8?

#AD282D sits directly opposite on the wheel. Softer options are the split-complements #AD2870 and #AD6528, which give the same contrast with far less vibration.

What colors go well with #28ada8?

For interface work: #F4FAFA as the surface, #C0EDEB for borders, #4B9B98 for secondary text, #B1244D as an accent and #186864 for hover and pressed states. For a palette, the analogous pair #28AD65 and #2870AD stays calm, while #AD282D is the loudest partner.

What is #28ada8 in CMYK for printing?

cmyk(77%, 0%, 3%, 32%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #28ada8 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 #28AD77; nudged cooler, #2686AF.

Which Tailwind color is closest to #28ada8?

The teal family — its 500 step is #14b8a6, ΔE2000 5.4 away. That is a visible difference, so define #28ada8 as a custom token rather than reaching for the built-in.

How do I use #28ada8 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#28ada8] or text-[#28ada8], 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 #28ada8 with 50% opacity?

rgba(40, 173, 168, 0.5), or #28ada880 in eight-digit hex. Over white that composites to #94D6D4; over black, #145754.

Is #28ada8 a web-safe color?

No. The nearest web-safe colour is #339999, ΔE2000 6.4 away. The palette only matters for legacy displays and some email clients now.

What does the color #28ada8 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 #28ada8?

The safest is same-hue elevation: linear-gradient(135deg, #40D3CD, #28ada8 45%, #186864). For more colour, a short hue run to #224394 keeps it rich without turning muddy.

Work with #28ada8 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #28ada8 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.