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cyan · cool

#28a9da

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

Token name suggestion: Signal Glacier

RGB
40, 169, 218
HSL
197°, 71%, 51%
CMYK
82, 23, 0, 15
Luminance
0.3389

#28a9da is a balanced vivid cyan, 197° on the wheel and 94/100 on the cool side. Put black text on it (7.78:1). As text it scores 2.70:1 on white — use #1C7EA4 instead. Nearest name is Deep Sky Blue, nearest Tailwind family is sky.

hsl(197 71% 51%)rgb(40 169 218)Base step 600AAA inkCool

At a glance

Every number on this page in one read: what #28a9da is made of, how bright it looks, and which way it leans.

Hex
#28a9da
Hue
197°
cyan
Saturation
71%
vivid
Lightness
51%
balanced
Brightness
85%
HSV value
Perceived
59%
weighted brightness
Luminance
0.3389
WCAG relative
Temperature
Cool
94/100 cool
Color family
Cyan
Tone
Vivid
Best ink
Black
7.78:1
Closest name
Deep Sky Blue
ΔE2000 6.6
Chroma
38.3
LCH, 0–130ish
OKLCH L
0.690
perceptual lightness
Tailwind
sky
500 · ΔE 4.6
Web-safe
#3399CC
nearest of 216
Where it sits
Hue197° of 360°
Saturation71%
Lightness51%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #28a9da.

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
Red1%
Green84%
Blue15%

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

Every format

HEX#28a9da
HEX (8-digit)#28a9daff
RGBrgb(40, 169, 218)
RGBArgba(40, 169, 218, 1)
HSLhsl(197, 71%, 51%)
HSV / HSBhsv(197, 82%, 85%)
HWBhwb(197 16% 15%)
CMYKcmyk(82%, 23%, 0%, 15%)
LABlab(64.9 -17.0 -34.3)
LCHlch(64.9 38.3 243.6)
OKLCHoklch(0.690 0.127 229.6)
XYZ (D65)xyz(27.71, 33.89, 71.40)
Decimal2664922
Display P3color(display-p3 0.157 0.663 0.855)
Web-safe#3399CC

Copy-ready code

every platformclick to select
/* CSS */
color: #28a9da;
background-color: #28a9da;
/* CSS custom property */
--brand: #28a9da;
/* Tailwind (arbitrary) */
class="text-[#28a9da] bg-[#28a9da]"
/* SCSS */
$brand: #28a9da;
/* SwiftUI */
Color(red: 0.157, green: 0.663, blue: 0.855)
/* UIKit */
UIColor(red: 0.157, green: 0.663, blue: 0.855, alpha: 1)
/* Android XML */
<color name="brand">#28A9DA</color>
/* Android Compose */
Color(0xFF28A9DA)
/* Flutter */
Color(0xFF28A9DA)
/* Python / OpenCV (BGR) */
(218, 169, 40)
/* Python / PIL (RGB) */
(40, 169, 218)
/* Java AWT */
new Color(40, 169, 218)
/* .NET */
Color.FromArgb(255, 40, 169, 218)
/* OpenGL / Unity (0–1) */
(0.1569f, 0.6627f, 0.8549f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{40,169,218}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #28a9da 85%, white);
border-color: color-mix(in oklab, #28a9da 40%, transparent);
/* theme-aware in one line */
color: light-dark(#13546D, #D3E7EE);
/* relative colour syntax */
--hover: hsl(from #28a9da 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: #F3F9FC;
  --brand-100: #E7F3F8;
  --brand-200: #C9E7F2;
  --brand-300: #9FD9EF;
  --brand-400: #6FC6E6;
  --brand-500: #40B2DE;
  --brand-600: #28a9da;
  --brand-700: #1E86AE;
  --brand-800: #186C8B;
  --brand-900: #154F65;
  --brand-950: #0D313F;
  --brand: #28a9da;
  --brand-ink: #000000;
  --brand-surface: #F4F9FA;
  --brand-border: #C0E0ED;
  --brand-hover: #2193BE;
  --brand-pressed: #1B7B9F;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142024;
    --brand-ink: #D3E7EE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F3F9FC',
        100: '#E7F3F8',
        200: '#C9E7F2',
        300: '#9FD9EF',
        400: '#6FC6E6',
        500: '#40B2DE',
        600: '#28a9da',
        700: '#1E86AE',
        800: '#186C8B',
        900: '#154F65',
        950: '#0D313F',
        DEFAULT: '#28a9da',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F3F9FC,
  '100': #E7F3F8,
  '200': #C9E7F2,
  '300': #9FD9EF,
  '400': #6FC6E6,
  '500': #40B2DE,
  '600': #28a9da,
  '700': #1E86AE,
  '800': #186C8B,
  '900': #154F65,
  '950': #0D313F,
);
$brand-base: #28a9da;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F3F9FC", "$type": "color" },
      "100": { "$value": "#E7F3F8", "$type": "color" },
      "200": { "$value": "#C9E7F2", "$type": "color" },
      "300": { "$value": "#9FD9EF", "$type": "color" },
      "400": { "$value": "#6FC6E6", "$type": "color" },
      "500": { "$value": "#40B2DE", "$type": "color" },
      "600": { "$value": "#28a9da", "$type": "color" },
      "700": { "$value": "#1E86AE", "$type": "color" },
      "800": { "$value": "#186C8B", "$type": "color" },
      "900": { "$value": "#154F65", "$type": "color" },
      "950": { "$value": "#0D313F", "$type": "color" }
    },
    "brandInk": { "$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 #28a9da · 7.78:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 2.70:1
AA fail · AA large fail · AAA fail
Aa
Black text · 7.78:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #28a9da as text scores 2.70:1 on white and 7.78:1 on black.
Best tinted ink on it, if plain black or white feels flat: #13546D at 3.09:1.

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
#1C7EA4 · 4.60:1
AA on white−13% L
#1C7EA4
The quick fox
#15607C · 7.01:1
AAA on white−22% L
#15607C
The quick fox
#28a9da · 7.78:1
AA on blackalready passes
#28a9da
The quick fox
#28a9da · 7.78:1
AAA on blackalready passes
#28a9da

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #24A0CF 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
#28a9da on white: 2.70:1
AA ✗ fail · AA-large · AAA
Aa
#28a9da on black: 7.78:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #28a9da as text on that neutral, and that neutral as text on #28a9da.

NeutralRatioBoth directions
White2.70:1AaAa
Slate 502.58:1AaAa
Slate 1002.46:1AaAa
Slate 2002.19:1AaAa
Slate 3001.82:1AaAa
Slate 4001.05:1AaAa
Slate 5001.76:1AaAa
Slate 6002.81:1AaAa
Slate 7003.84:1AaAa
Slate 8005.42:1AaAa
Slate 9006.61:1AaAa
Black7.78:1AaAa
Colour vision deficiency
true color
protanopia · #90A7DC
deuteranopia · #7896D9
tritanopia · #00B7B9

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. #28a9da is pinned to step 600; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F3F9FC
#E7F3F8
#C9E7F2
#9FD9EF
#6FC6E6
#40B2DE
#28a9da
#1E86AE
#186C8B
#154F65
#0D313F
Base = 600Lightest = 50 · #F3F9FCDarkest = 950 · #0D313FText 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 0.032 229.6);
  --brand-100: oklch(0.94 0.051 229.6);
  --brand-200: oklch(0.88 0.076 229.6);
  --brand-300: oklch(0.80 0.099 229.6);
  --brand-400: oklch(0.72 0.117 229.6);
  --brand-500: oklch(0.64 0.127 229.6);
  --brand-600: oklch(0.56 0.127 229.6);
  --brand-700: oklch(0.48 0.119 229.6);
  --brand-800: oklch(0.40 0.107 229.6);
  --brand-900: oklch(0.32 0.089 229.6);
  --brand-950: oklch(0.24 0.070 229.6);
}

Colors that work with #28a9da

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#C0E0ED
Hairlines and dividers
Muted text#4B859B
Captions on the surface
Accent#DF2823
Second voice, not a rival
Dark variant#13546D
Hover, pressed, headers
Light variant#E9F6FB
Selected rows, tints
Dark surface#142024
Dark-mode background
Hover#2193BE
One step down in lightness
Pressed#1B7B9F
Two steps down
Disabled#AAC0C9
Chroma pulled out
Focus ring#2EB5E9
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 #28a9da

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 #13546D
Safe as a 1px border on white
No — use #24A0CF

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
  • Weight49/100
  • 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#DA5928
Analogous left#28DAB2
Analogous right#2850DA
Split-complement 1#DA2850
Split-complement 2#DAB228
Triadic 1#DA28A9
Triadic 2#A9DA28
Tetradic#B228DA
On the wheel
Base+30°−30°+120°+240°+180°197°

#28a9da sits at 197°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red15.7%
Green66.3%
Blue85.5%
R · 0–255
40
0x28
G · 0–255
169
0xa9
B · 0–255
218
0xda

CMYK percentages

Cyan81.7%
Magenta22.5%
Yellow0.0%
Key (black)14.5%

Total ink coverage is 119%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#28a9da text on a black background

contrast 7.78:1

Card sample

#28a9da text on a white background

contrast 2.70:1

Card sample

#28a9da on grey

2.46:1

#28a9da on its own surface

2.54:1

#28a9da on its dark surface

6.16:1

CSS3 live lab

Text font color

The quick brown fox

color: #28a9da;
Background color
Panel with #28a9da background
background-color: #28a9da;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #28a9da;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(40, 169, 218, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(40, 169, 218, 0.45);
Border & gradient
Gradient panel
border: 3px solid #28a9da;
background: linear-gradient(135deg, #28a9da, #2832DA);
Gradient text

Gradient headline

background: linear-gradient(90deg, #28a9da, #4A28DA);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #28a9da;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #28a9da;
caret-color: #28a9da;
Left rule
Pull quote or callout
border-left: 4px solid #28a9da;
Ring + tint
Selected chip
background: #E9F6FB;
box-shadow: inset 0 0 0 2px #28a9da;
Conic badge
68%
background: conic-gradient(#28a9da 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #28a9da 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, 169, 218, 0.5)
rgb(40 169 218 / 50%)
#28a9da80
hsl(197 71% 51% / 50%)
color-mix(in srgb, #28a9da 50%, transparent)
Alpha8-digit hexFlat on white
10%#28a9da1a#EAF6FB
20%#28a9da33#D4EEF8
40%#28a9da66#A9DDF0
60%#28a9da99#7ECBE9
80%#28a9dacc#53BAE1

Gradients from #28a9da

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, #5CBEE3, #28a9da 45%, #13546D);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #28a9da, #2521C2);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #28a9da, #DA5928);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #76C8E7 0%, #28a9da 45%, #13546D 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%, #54E1B6 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #4258DE 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #13546D 0%, transparent 65%), #28a9da;

Monochromatic scale

Palettes built from #28a9da

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.

#28a9da 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 7.78:1.

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.

#28a9da, answered

What color is #28a9da?

#28a9da is a balanced vivid cyan, closest to Deep Sky Blue (ΔE2000 6.6). It sits at 197° on the hue wheel with 71% saturation and 51% lightness, which reads as cool.

What is the RGB value of #28a9da?

rgb(40, 169, 218) — 40 red, 169 green and 218 blue out of 255, or 15.7% / 66.3% / 85.5% by channel.

What is #28a9da in HSL and HSV?

hsl(197, 71%, 51%) and hsv(197, 82%, 85%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #28a9da a light or a dark color?

It is a mid-tone. Relative luminance is 0.3389 and perceived brightness is 59%, so black text on it reaches 7.78:1.

Should I use black or white text on #28a9da?

Black. It scores 7.78:1 against #28a9da, versus 2.70:1 for white — AAA at any size.

Is #28a9da accessible on a white background?

#28a9da on white scores 2.70:1, which fails WCAG AA at every size. Darken it to #1C7EA4 to reach 4.5:1, or #15607C for 7:1.

What is the complementary color of #28a9da?

#DA5928 sits directly opposite on the wheel. Softer options are the split-complements #DA2850 and #DAB228, which give the same contrast with far less vibration.

What colors go well with #28a9da?

For interface work: #F4F9FA as the surface, #C0E0ED for borders, #4B859B for secondary text, #DF2823 as an accent and #13546D for hover and pressed states. For a palette, the analogous pair #28DAB2 and #2850DA stays calm, while #DA5928 is the loudest partner.

What is #28a9da in CMYK for printing?

cmyk(82%, 23%, 0%, 15%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #28a9da 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 #28DACA; nudged cooler, #2692DC.

Which Tailwind color is closest to #28a9da?

The sky family — its 500 step is #0ea5e9, ΔE2000 4.6 away. That is a visible difference, so define #28a9da as a custom token rather than reaching for the built-in.

How do I use #28a9da in Tailwind CSS?

Inline it as an arbitrary value with bg-[#28a9da] or text-[#28a9da], 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 #28a9da with 50% opacity?

rgba(40, 169, 218, 0.5), or #28a9da80 in eight-digit hex. Over white that composites to #94D4ED; over black, #14556D.

Is #28a9da a web-safe color?

No. The nearest web-safe colour is #3399CC, ΔE2000 5.2 away. The palette only matters for legacy displays and some email clients now.

What does the color #28a9da 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 #28a9da?

The safest is same-hue elevation: linear-gradient(135deg, #5CBEE3, #28a9da 45%, #13546D). For more colour, a short hue run to #2521C2 keeps it rich without turning muddy.

Work with #28a9da in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #28a9da at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.