Skip to content
cyan · cool

#339c9b

a dark, vivid cyan · cool · closest name: Cadet Blue

Token name suggestion: Slate Lagoon

RGB
51, 156, 155
HSL
179°, 51%, 41%
CMYK
67, 0, 1, 39
Luminance
0.2685

#339c9b is a dark vivid cyan, 179° on the wheel and 87/100 on the cool side. Put black text on it (6.37:1). As text it scores 3.30:1 on white — large text only. Nearest name is Cadet Blue, nearest Tailwind family is teal.

hsl(179 51% 41%)rgb(51 156 155)Base step 700AA inkCool

At a glance

Every number on this page in one read: what #339c9b is made of, how bright it looks, and which way it leans.

Hex
#339c9b
Hue
179°
cyan
Saturation
51%
vivid
Lightness
41%
dark
Brightness
61%
HSV value
Perceived
52%
weighted brightness
Luminance
0.2685
WCAG relative
Temperature
Cool
87/100 cool
Color family
Cyan
Tone
Vivid
Best ink
Black
6.37:1
Closest name
Cadet Blue
ΔE2000 5.3
Chroma
30.5
LCH, 0–130ish
OKLCH L
0.634
perceptual lightness
Tailwind
teal
500 · ΔE 10.1
Web-safe
#339999
nearest of 216
Where it sits
Hue179° of 360°
Saturation51%
Lightness41%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #339c9b.

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
Red3%
Green89%
Blue9%

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

Every format

HEX#339c9b
HEX (8-digit)#339c9bff
RGBrgb(51, 156, 155)
RGBArgba(51, 156, 155, 1)
HSLhsl(179, 51%, 41%)
HSV / HSBhsv(179, 67%, 61%)
HWBhwb(179 20% 39%)
CMYKcmyk(67%, 0%, 1%, 39%)
LABlab(58.8 -29.3 -8.2)
LCHlch(58.8 30.5 195.6)
OKLCHoklch(0.634 0.093 194.1)
XYZ (D65)xyz(19.17, 26.85, 35.18)
Decimal3382427
Display P3color(display-p3 0.200 0.612 0.608)
Web-safe#339999

Copy-ready code

every platformclick to select
/* CSS */
color: #339c9b;
background-color: #339c9b;
/* CSS custom property */
--brand: #339c9b;
/* Tailwind (arbitrary) */
class="text-[#339c9b] bg-[#339c9b]"
/* SCSS */
$brand: #339c9b;
/* SwiftUI */
Color(red: 0.200, green: 0.612, blue: 0.608)
/* UIKit */
UIColor(red: 0.200, green: 0.612, blue: 0.608, alpha: 1)
/* Android XML */
<color name="brand">#339C9B</color>
/* Android Compose */
Color(0xFF339C9B)
/* Flutter */
Color(0xFF339C9B)
/* Python / OpenCV (BGR) */
(155, 156, 51)
/* Python / PIL (RGB) */
(51, 156, 155)
/* Java AWT */
new Color(51, 156, 155)
/* .NET */
Color.FromArgb(255, 51, 156, 155)
/* OpenGL / Unity (0–1) */
(0.2000f, 0.6118f, 0.6078f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{51,156,155}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #339c9b 85%, white);
border-color: color-mix(in oklab, #339c9b 40%, transparent);
/* theme-aware in one line */
color: light-dark(#1F605F, #D3EEEE);
/* relative colour syntax */
--hover: hsl(from #339c9b 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: #F4FAFA;
  --brand-100: #EAF6F6;
  --brand-200: #CFEDEC;
  --brand-300: #AAE3E3;
  --brand-400: #80D6D5;
  --brand-500: #56C8C7;
  --brand-600: #3CB8B7;
  --brand-700: #339c9b;
  --brand-800: #287B7A;
  --brand-900: #215A59;
  --brand-950: #143838;
  --brand: #339c9b;
  --brand-ink: #000000;
  --brand-surface: #F4FAFA;
  --brand-border: #C2EBEA;
  --brand-hover: #2A8180;
  --brand-pressed: #216666;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142424;
    --brand-ink: #D3EEEE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F4FAFA',
        100: '#EAF6F6',
        200: '#CFEDEC',
        300: '#AAE3E3',
        400: '#80D6D5',
        500: '#56C8C7',
        600: '#3CB8B7',
        700: '#339c9b',
        800: '#287B7A',
        900: '#215A59',
        950: '#143838',
        DEFAULT: '#339c9b',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F4FAFA,
  '100': #EAF6F6,
  '200': #CFEDEC,
  '300': #AAE3E3,
  '400': #80D6D5,
  '500': #56C8C7,
  '600': #3CB8B7,
  '700': #339c9b,
  '800': #287B7A,
  '900': #215A59,
  '950': #143838,
);
$brand-base: #339c9b;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F4FAFA", "$type": "color" },
      "100": { "$value": "#EAF6F6", "$type": "color" },
      "200": { "$value": "#CFEDEC", "$type": "color" },
      "300": { "$value": "#AAE3E3", "$type": "color" },
      "400": { "$value": "#80D6D5", "$type": "color" },
      "500": { "$value": "#56C8C7", "$type": "color" },
      "600": { "$value": "#3CB8B7", "$type": "color" },
      "700": { "$value": "#339c9b", "$type": "color" },
      "800": { "$value": "#287B7A", "$type": "color" },
      "900": { "$value": "#215A59", "$type": "color" },
      "950": { "$value": "#143838", "$type": "color" }
    },
    "brandInk": { "$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 #339c9b · 6.37:1
Use #000000AA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 3.30:1
AA fail · AA large pass · AAA fail
Aa
Black text · 6.37:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #339c9b as text scores 3.30:1 on white and 6.37:1 on black.
Best tinted ink on it, if plain black or white feels flat: #1F605F at 2.20:1.

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
#2A8180 · 4.62:1
AA on white−7% L
#2A8180
The quick fox
#206262 · 7.04:1
AAA on white−15% L
#206262
The quick fox
#339c9b · 6.37:1
AA on blackalready passes
#339c9b
The quick fox
#36A4A3 · 7.00:1
AAA on black+2% L
#36A4A3

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #339C9B 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
#339c9b on white: 3.30:1
AA ✗ fail · AA-large · AAA
Aa
#339c9b on black: 6.37:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #339c9b as text on that neutral, and that neutral as text on #339c9b.

NeutralRatioBoth directions
White3.30:1AaAa
Slate 503.15:1AaAa
Slate 1003.01:1AaAa
Slate 2002.67:1AaAa
Slate 3002.22:1AaAa
Slate 4001.29:1AaAa
Slate 5001.44:1AaAa
Slate 6002.30:1AaAa
Slate 7003.14:1AaAa
Slate 8004.44:1AaAa
Slate 9005.41:1AaAa
Black6.37:1AaAa
Colour vision deficiency
true color
protanopia · #92949B
deuteranopia · #82899C
tritanopia · #00A19B

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. #339c9b 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.

#F4FAFA
#EAF6F6
#CFEDEC
#AAE3E3
#80D6D5
#56C8C7
#3CB8B7
#339c9b
#287B7A
#215A59
#143838
Base = 700Lightest = 50 · #F4FAFADarkest = 950 · #143838Text 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 0.023 194.1);
  --brand-100: oklch(0.94 0.037 194.1);
  --brand-200: oklch(0.88 0.056 194.1);
  --brand-300: oklch(0.80 0.073 194.1);
  --brand-400: oklch(0.72 0.086 194.1);
  --brand-500: oklch(0.64 0.093 194.1);
  --brand-600: oklch(0.56 0.093 194.1);
  --brand-700: oklch(0.48 0.088 194.1);
  --brand-800: oklch(0.40 0.079 194.1);
  --brand-900: oklch(0.32 0.065 194.1);
  --brand-950: oklch(0.24 0.051 194.1);
}

Colors that work with #339c9b

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#C2EBEA
Hairlines and dividers
Muted text#4B9B9A
Captions on the surface
Accent#A02F4C
Second voice, not a rival
Dark variant#1F605F
Hover, pressed, headers
Light variant#ECF9F9
Selected rows, tints
Dark surface#142424
Dark-mode background
Hover#2A8180
One step down in lightness
Pressed#216666
Two steps down
Disabled#8BB5B4
Chroma pulled out
Focus ring#2DB7B5
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 #339c9b

Derived from its contrast, chroma and lightness — not from taste.

Works well for
  • Headings from 24px up on white
  • 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
  • Small text on white — under 4.5:1
  • 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
24px / 18.66px bold
Safe as a fill behind white type
No — use #1F605F
Safe as a 1px border on white
Yes

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
  • Weight59/100
  • 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#9C3334
Analogous left#339C66
Analogous right#33699C
Split-complement 1#9C3369
Split-complement 2#9C6633
Triadic 1#9B339C
Triadic 2#9C9B33
Tetradic#66339C
On the wheel
Base+30°−30°+120°+240°+180°179°

#339c9b sits at 179°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red20.0%
Green61.2%
Blue60.8%
R · 0–255
51
0x33
G · 0–255
156
0x9c
B · 0–255
155
0x9b

CMYK percentages

Cyan67.3%
Magenta0.0%
Yellow0.6%
Key (black)38.8%

Total ink coverage is 107%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#339c9b text on a black background

contrast 6.37:1

Card sample

#339c9b text on a white background

contrast 3.30:1

Card sample

#339c9b on grey

3.01:1

#339c9b on its own surface

3.12:1

#339c9b on its dark surface

4.87:1

CSS3 live lab

Text font color

The quick brown fox

color: #339c9b;
Background color
Panel with #339c9b background
background-color: #339c9b;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #339c9b;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(51, 156, 155, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(51, 156, 155, 0.45);
Border & gradient
Gradient panel
border: 3px solid #339c9b;
background: linear-gradient(135deg, #339c9b, #33579C);
Gradient text

Gradient headline

background: linear-gradient(90deg, #339c9b, #333D9C);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #339c9b;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #339c9b;
caret-color: #339c9b;
Left rule
Pull quote or callout
border-left: 4px solid #339c9b;
Ring + tint
Selected chip
background: #ECF9F9;
box-shadow: inset 0 0 0 2px #339c9b;
Conic badge
68%
background: conic-gradient(#339c9b 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #339c9b 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(51, 156, 155, 0.5)
rgb(51 156 155 / 50%)
#339c9b80
hsl(179 51% 41% / 50%)
color-mix(in srgb, #339c9b 50%, transparent)
Alpha8-digit hexFlat on white
10%#339c9b1a#EBF5F5
20%#339c9b33#D6EBEB
40%#339c9b66#ADD7D7
60%#339c9b99#85C4C3
80%#339c9bcc#5CB0AF

Gradients from #339c9b

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, #49C3C2, #339c9b 45%, #1F605F);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #339c9b, #2B4385);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #339c9b, #9C3334);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #60CBCA 0%, #339c9b 45%, #1F605F 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%, #41C175 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #3B6EB3 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #1F605F 0%, transparent 65%), #339c9b;

Monochromatic scale

Palettes built from #339c9b

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.

#339c9b 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 6.37:1.

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.

#339c9b, answered

What color is #339c9b?

#339c9b is a dark vivid cyan, closest to Cadet Blue (ΔE2000 5.3). It sits at 179° on the hue wheel with 51% saturation and 41% lightness, which reads as cool.

What is the RGB value of #339c9b?

rgb(51, 156, 155) — 51 red, 156 green and 155 blue out of 255, or 20% / 61.2% / 60.8% by channel.

What is #339c9b in HSL and HSV?

hsl(179, 51%, 41%) and hsv(179, 67%, 61%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #339c9b a light or a dark color?

It is a mid-tone. Relative luminance is 0.2685 and perceived brightness is 52%, so black text on it reaches 6.37:1.

Should I use black or white text on #339c9b?

Black. It scores 6.37:1 against #339c9b, versus 3.30:1 for white — AA at any size.

Is #339c9b accessible on a white background?

#339c9b on white scores 3.30:1, which only clears AA for large text — 18.66px bold or 24px regular and up. Darken it to #2A8180 to reach 4.5:1, or #206262 for 7:1.

What is the complementary color of #339c9b?

#9C3334 sits directly opposite on the wheel. Softer options are the split-complements #9C3369 and #9C6633, which give the same contrast with far less vibration.

What colors go well with #339c9b?

For interface work: #F4FAFA as the surface, #C2EBEA for borders, #4B9B9A for secondary text, #A02F4C as an accent and #1F605F for hover and pressed states. For a palette, the analogous pair #339C66 and #33699C stays calm, while #9C3334 is the loudest partner.

What is #339c9b in CMYK for printing?

cmyk(67%, 0%, 1%, 39%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #339c9b 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 #339C74; nudged cooler, #31799E.

Which Tailwind color is closest to #339c9b?

The teal family — its 500 step is #14b8a6, ΔE2000 10.1 away. That is a visible difference, so define #339c9b as a custom token rather than reaching for the built-in.

How do I use #339c9b in Tailwind CSS?

Inline it as an arbitrary value with bg-[#339c9b] or text-[#339c9b], 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 #339c9b with 50% opacity?

rgba(51, 156, 155, 0.5), or #339c9b80 in eight-digit hex. Over white that composites to #99CECD; over black, #1A4E4E.

Is #339c9b a web-safe color?

No. The nearest web-safe colour is #339999, ΔE2000 1 away. The palette only matters for legacy displays and some email clients now.

What does the color #339c9b 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 #339c9b?

The safest is same-hue elevation: linear-gradient(135deg, #49C3C2, #339c9b 45%, #1F605F). For more colour, a short hue run to #2B4385 keeps it rich without turning muddy.

Work with #339c9b in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #339c9b at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.