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cyan · cool

#398e8f

a dark, soft cyan · cool · closest name: Dark Cyan

Token name suggestion: Slate Reef

RGB
57, 142, 143
HSL
181°, 43%, 39%
CMYK
60, 1, 0, 44
Luminance
0.2220

#398e8f is a dark soft cyan, 181° on the wheel and 88/100 on the cool side. Put black text on it (5.44:1). As text it scores 3.86:1 on white — large text only. Nearest name is Dark Cyan, nearest Tailwind family is teal.

hsl(181 43% 39%)rgb(57 142 143)Base step 700AA inkCool

At a glance

Every number on this page in one read: what #398e8f is made of, how bright it looks, and which way it leans.

Hex
#398e8f
Hue
181°
cyan
Saturation
43%
soft
Lightness
39%
dark
Brightness
56%
HSV value
Perceived
48%
weighted brightness
Luminance
0.2220
WCAG relative
Temperature
Cool
88/100 cool
Color family
Cyan
Tone
Soft
Best ink
Black
5.44:1
Closest name
Dark Cyan
ΔE2000 3.3
Chroma
26.2
LCH, 0–130ish
OKLCH L
0.596
perceptual lightness
Tailwind
teal
500 · ΔE 14.5
Web-safe
#339999
nearest of 216
Where it sits
Hue181° of 360°
Saturation43%
Lightness39%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #398e8f.

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
Red4%
Green87%
Blue9%

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

Every format

HEX#398e8f
HEX (8-digit)#398e8fff
RGBrgb(57, 142, 143)
RGBArgba(57, 142, 143, 1)
HSLhsl(181, 43%, 39%)
HSV / HSBhsv(181, 60%, 56%)
HWBhwb(181 22% 44%)
CMYKcmyk(60%, 1%, 0%, 44%)
LABlab(54.2 -24.9 -8.2)
LCHlch(54.2 26.2 198.2)
OKLCHoklch(0.596 0.081 196.3)
XYZ (D65)xyz(16.32, 22.20, 29.41)
Decimal3772047
Display P3color(display-p3 0.224 0.557 0.561)
Web-safe#339999

Copy-ready code

every platformclick to select
/* CSS */
color: #398e8f;
background-color: #398e8f;
/* CSS custom property */
--brand: #398e8f;
/* Tailwind (arbitrary) */
class="text-[#398e8f] bg-[#398e8f]"
/* SCSS */
$brand: #398e8f;
/* SwiftUI */
Color(red: 0.224, green: 0.557, blue: 0.561)
/* UIKit */
UIColor(red: 0.224, green: 0.557, blue: 0.561, alpha: 1)
/* Android XML */
<color name="brand">#398E8F</color>
/* Android Compose */
Color(0xFF398E8F)
/* Flutter */
Color(0xFF398E8F)
/* Python / OpenCV (BGR) */
(143, 142, 57)
/* Python / PIL (RGB) */
(57, 142, 143)
/* Java AWT */
new Color(57, 142, 143)
/* .NET */
Color.FromArgb(255, 57, 142, 143)
/* OpenGL / Unity (0–1) */
(0.2235f, 0.5569f, 0.5608f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{57,142,143}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #398e8f 85%, white);
border-color: color-mix(in oklab, #398e8f 40%, transparent);
/* theme-aware in one line */
color: light-dark(#245B5B, #D3EDEE);
/* relative colour syntax */
--hover: hsl(from #398e8f 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: #F5FAFA;
  --brand-100: #EBF5F5;
  --brand-200: #D1EAEA;
  --brand-300: #AFDEDF;
  --brand-400: #87CECF;
  --brand-500: #5FBEBF;
  --brand-600: #46AEAF;
  --brand-700: #398e8f;
  --brand-800: #2F7475;
  --brand-900: #255555;
  --brand-950: #173535;
  --brand: #398e8f;
  --brand-ink: #000000;
  --brand-surface: #F4FAFA;
  --brand-border: #C5E7E8;
  --brand-hover: #2F7575;
  --brand-pressed: #255B5C;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142424;
    --brand-ink: #D3EDEE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F5FAFA',
        100: '#EBF5F5',
        200: '#D1EAEA',
        300: '#AFDEDF',
        400: '#87CECF',
        500: '#5FBEBF',
        600: '#46AEAF',
        700: '#398e8f',
        800: '#2F7475',
        900: '#255555',
        950: '#173535',
        DEFAULT: '#398e8f',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F5FAFA,
  '100': #EBF5F5,
  '200': #D1EAEA,
  '300': #AFDEDF,
  '400': #87CECF,
  '500': #5FBEBF,
  '600': #46AEAF,
  '700': #398e8f,
  '800': #2F7475,
  '900': #255555,
  '950': #173535,
);
$brand-base: #398e8f;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F5FAFA", "$type": "color" },
      "100": { "$value": "#EBF5F5", "$type": "color" },
      "200": { "$value": "#D1EAEA", "$type": "color" },
      "300": { "$value": "#AFDEDF", "$type": "color" },
      "400": { "$value": "#87CECF", "$type": "color" },
      "500": { "$value": "#5FBEBF", "$type": "color" },
      "600": { "$value": "#46AEAF", "$type": "color" },
      "700": { "$value": "#398e8f", "$type": "color" },
      "800": { "$value": "#2F7475", "$type": "color" },
      "900": { "$value": "#255555", "$type": "color" },
      "950": { "$value": "#173535", "$type": "color" }
    },
    "brandInk": { "$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 #398e8f · 5.44:1
Use #000000AA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 3.86:1
AA fail · AA large pass · AAA fail
Aa
Black text · 5.44:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #398e8f as text scores 3.86:1 on white and 5.44:1 on black.
Best tinted ink on it, if plain black or white feels flat: #245B5B at 2.00:1.

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
#337F80 · 4.68:1
AA on white−4% L
#337F80
The quick fox
#265F60 · 7.27:1
AAA on white−13% L
#265F60
The quick fox
#398e8f · 5.44:1
AA on blackalready passes
#398e8f
The quick fox
#42A4A5 · 7.09:1
AAA on black+6% L
#42A4A5

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #398E8F 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
#398e8f on white: 3.86:1
AA ✗ fail · AA-large · AAA
Aa
#398e8f on black: 5.44:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #398e8f as text on that neutral, and that neutral as text on #398e8f.

NeutralRatioBoth directions
White3.86:1AaAa
Slate 503.69:1AaAa
Slate 1003.52:1AaAa
Slate 2003.13:1AaAa
Slate 3002.60:1AaAa
Slate 4001.51:1AaAa
Slate 5001.23:1AaAa
Slate 6001.96:1AaAa
Slate 7002.68:1AaAa
Slate 8003.79:1AaAa
Slate 9004.62:1AaAa
Black5.44:1AaAa
Colour vision deficiency
true color
protanopia · #85888F
deuteranopia · #777D90
tritanopia · #00928E

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. #398e8f 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.

#F5FAFA
#EBF5F5
#D1EAEA
#AFDEDF
#87CECF
#5FBEBF
#46AEAF
#398e8f
#2F7475
#255555
#173535
Base = 700Lightest = 50 · #F5FAFADarkest = 950 · #173535Text 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 0.020 196.3);
  --brand-100: oklch(0.94 0.032 196.3);
  --brand-200: oklch(0.88 0.048 196.3);
  --brand-300: oklch(0.80 0.063 196.3);
  --brand-400: oklch(0.72 0.074 196.3);
  --brand-500: oklch(0.64 0.081 196.3);
  --brand-600: oklch(0.56 0.081 196.3);
  --brand-700: oklch(0.48 0.076 196.3);
  --brand-800: oklch(0.40 0.068 196.3);
  --brand-900: oklch(0.32 0.057 196.3);
  --brand-950: oklch(0.24 0.044 196.3);
}

Colors that work with #398e8f

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#C5E7E8
Hairlines and dividers
Muted text#4B9A9B
Captions on the surface
Accent#93354B
Second voice, not a rival
Dark variant#245B5B
Hover, pressed, headers
Light variant#EDF8F8
Selected rows, tints
Dark surface#142424
Dark-mode background
Hover#2F7575
One step down in lightness
Pressed#255B5C
Two steps down
Disabled#86B1B2
Chroma pulled out
Focus ring#34A7A9
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 #398e8f

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
  • Charts, tags and secondary surfaces
  • Headers, footers and dark-mode surfaces
  • Brand accents, badges and data highlights
Use with care
  • Small text on white — under 4.5:1
  • 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 #245B5B
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.

The muted chroma softens the association — it reads considered rather than loud, which suits long-form and data-heavy screens. 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
  • Weight61/100
  • 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#8F3A39
Analogous left#398F65
Analogous right#39638F
Split-complement 1#8F3963
Split-complement 2#8F6539
Triadic 1#8F398E
Triadic 2#8E8F39
Tetradic#65398F
On the wheel
Base+30°−30°+120°+240°+180°181°

#398e8f sits at 181°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red22.4%
Green55.7%
Blue56.1%
R · 0–255
57
0x39
G · 0–255
142
0x8e
B · 0–255
143
0x8f

CMYK percentages

Cyan60.1%
Magenta0.7%
Yellow0.0%
Key (black)43.9%

Total ink coverage is 105%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#398e8f text on a black background

contrast 5.44:1

Card sample

#398e8f text on a white background

contrast 3.86:1

Card sample

#398e8f on grey

3.52:1

#398e8f on its own surface

3.66:1

#398e8f on its dark surface

4.16:1

CSS3 live lab

Text font color

The quick brown fox

color: #398e8f;
Background color
Panel with #398e8f background
background-color: #398e8f;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #398e8f;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(57, 142, 143, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(57, 142, 143, 0.45);
Border & gradient
Gradient panel
border: 3px solid #398e8f;
background: linear-gradient(135deg, #398e8f, #39558F);
Gradient text

Gradient headline

background: linear-gradient(90deg, #398e8f, #393F8F);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #398e8f;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #398e8f;
caret-color: #398e8f;
Left rule
Pull quote or callout
border-left: 4px solid #398e8f;
Ring + tint
Selected chip
background: #EDF8F8;
box-shadow: inset 0 0 0 2px #398e8f;
Conic badge
68%
background: conic-gradient(#398e8f 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #398e8f 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(57, 142, 143, 0.5)
rgb(57 142 143 / 50%)
#398e8f80
hsl(181 43% 39% / 50%)
color-mix(in srgb, #398e8f 50%, transparent)
Alpha8-digit hexFlat on white
10%#398e8f1a#EBF4F4
20%#398e8f33#D7E8E9
40%#398e8f66#B0D2D2
60%#398e8f99#88BBBC
80%#398e8fcc#61A5A5

Gradients from #398e8f

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, #4DB7B8, #398e8f 45%, #245B5B);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #398e8f, #304279);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #398e8f, #8F3A39);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #63C0C1 0%, #398e8f 45%, #245B5B 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%, #48B376 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #426AA5 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #245B5B 0%, transparent 65%), #398e8f;

Monochromatic scale

Palettes built from #398e8f

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.

#398e8f 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 5.44:1.

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.

#398e8f, answered

What color is #398e8f?

#398e8f is a dark soft cyan, closest to Dark Cyan (ΔE2000 3.3). It sits at 181° on the hue wheel with 43% saturation and 39% lightness, which reads as cool.

What is the RGB value of #398e8f?

rgb(57, 142, 143) — 57 red, 142 green and 143 blue out of 255, or 22.4% / 55.7% / 56.1% by channel.

What is #398e8f in HSL and HSV?

hsl(181, 43%, 39%) and hsv(181, 60%, 56%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #398e8f a light or a dark color?

It is a mid-tone. Relative luminance is 0.2220 and perceived brightness is 48%, so black text on it reaches 5.44:1.

Should I use black or white text on #398e8f?

Black. It scores 5.44:1 against #398e8f, versus 3.86:1 for white — AA at any size.

Is #398e8f accessible on a white background?

#398e8f on white scores 3.86:1, which only clears AA for large text — 18.66px bold or 24px regular and up. Darken it to #337F80 to reach 4.5:1, or #265F60 for 7:1.

What is the complementary color of #398e8f?

#8F3A39 sits directly opposite on the wheel. Softer options are the split-complements #8F3963 and #8F6539, which give the same contrast with far less vibration.

What colors go well with #398e8f?

For interface work: #F4FAFA as the surface, #C5E7E8 for borders, #4B9A9B for secondary text, #93354B as an accent and #245B5B for hover and pressed states. For a palette, the analogous pair #398F65 and #39638F stays calm, while #8F3A39 is the loudest partner.

What is #398e8f in CMYK for printing?

cmyk(60%, 1%, 0%, 44%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #398e8f 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 #398F70; nudged cooler, #377091.

Which Tailwind color is closest to #398e8f?

The teal family — its 500 step is #14b8a6, ΔE2000 14.5 away. That is a visible difference, so define #398e8f as a custom token rather than reaching for the built-in.

How do I use #398e8f in Tailwind CSS?

Inline it as an arbitrary value with bg-[#398e8f] or text-[#398e8f], 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 #398e8f with 50% opacity?

rgba(57, 142, 143, 0.5), or #398e8f80 in eight-digit hex. Over white that composites to #9CC7C7; over black, #1D4748.

Is #398e8f a web-safe color?

No. The nearest web-safe colour is #339999, ΔE2000 3.8 away. The palette only matters for legacy displays and some email clients now.

What does the color #398e8f mean?

As a cyan, it reads clean, technical, fresh. Cyan reads as water, air and infrastructure: cool, hygienic, engineered. At this moderate chroma the association is present but not shouted.

What gradient works with #398e8f?

The safest is same-hue elevation: linear-gradient(135deg, #4DB7B8, #398e8f 45%, #245B5B). For more colour, a short hue run to #304279 keeps it rich without turning muddy.

Work with #398e8f in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #398e8f at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.