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blue · cool

#398bbc

a balanced, vivid blue · cool · closest name: Steel Blue

Token name suggestion: True Sapphire

RGB
57, 139, 188
HSL
202°, 54%, 48%
CMYK
70, 26, 0, 26
Luminance
0.2297

#398bbc is a balanced vivid blue, 202° on the wheel and 97/100 on the cool side. Put black text on it (5.59:1). As text it scores 3.75:1 on white — large text only. Nearest name is Steel Blue, nearest Tailwind family is sky.

hsl(202 54% 48%)rgb(57 139 188)Base step 600AA inkCool

At a glance

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

Hex
#398bbc
Hue
202°
blue
Saturation
54%
vivid
Lightness
48%
balanced
Brightness
74%
HSV value
Perceived
50%
weighted brightness
Luminance
0.2297
WCAG relative
Temperature
Cool
97/100 cool
Color family
Blue
Tone
Vivid
Best ink
Black
5.59:1
Closest name
Steel Blue
ΔE2000 4.2
Chroma
34.0
LCH, 0–130ish
OKLCH L
0.608
perceptual lightness
Tailwind
sky
500 · ΔE 8.9
Web-safe
#3399CC
nearest of 216
Where it sits
Hue202° of 360°
Saturation54%
Lightness48%
Saturation × lightness field

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

Temperature
Warm ← → Cool97% 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%
Green80%
Blue16%

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

Every format

HEX#398bbc
HEX (8-digit)#398bbcff
RGBrgb(57, 139, 188)
RGBArgba(57, 139, 188, 1)
HSLhsl(202, 54%, 48%)
HSV / HSBhsv(202, 70%, 74%)
HWBhwb(202 22% 26%)
CMYKcmyk(70%, 26%, 0%, 26%)
LABlab(55.0 -8.8 -32.8)
LCHlch(55.0 34.0 254.9)
OKLCHoklch(0.608 0.108 238.5)
XYZ (D65)xyz(19.99, 22.96, 50.95)
Decimal3771324
Display P3color(display-p3 0.224 0.545 0.737)
Web-safe#3399CC

Copy-ready code

every platformclick to select
/* CSS */
color: #398bbc;
background-color: #398bbc;
/* CSS custom property */
--brand: #398bbc;
/* Tailwind (arbitrary) */
class="text-[#398bbc] bg-[#398bbc]"
/* SCSS */
$brand: #398bbc;
/* SwiftUI */
Color(red: 0.224, green: 0.545, blue: 0.737)
/* UIKit */
UIColor(red: 0.224, green: 0.545, blue: 0.737, alpha: 1)
/* Android XML */
<color name="brand">#398BBC</color>
/* Android Compose */
Color(0xFF398BBC)
/* Flutter */
Color(0xFF398BBC)
/* Python / OpenCV (BGR) */
(188, 139, 57)
/* Python / PIL (RGB) */
(57, 139, 188)
/* Java AWT */
new Color(57, 139, 188)
/* .NET */
Color.FromArgb(255, 57, 139, 188)
/* OpenGL / Unity (0–1) */
(0.2235f, 0.5451f, 0.7373f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{57,139,188}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #398bbc 85%, white);
border-color: color-mix(in oklab, #398bbc 40%, transparent);
/* theme-aware in one line */
color: light-dark(#1E4862, #D3E4EE);
/* relative colour syntax */
--hover: hsl(from #398bbc 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: #F4F8FB;
  --brand-100: #E9F1F6;
  --brand-200: #CEE2ED;
  --brand-300: #A9CFE5;
  --brand-400: #7EB6D8;
  --brand-500: #539ECB;
  --brand-600: #398bbc;
  --brand-700: #2F749D;
  --brand-800: #265D7D;
  --brand-900: #1F455B;
  --brand-950: #132B39;
  --brand: #398bbc;
  --brand-ink: #000000;
  --brand-surface: #F4F8FA;
  --brand-border: #C0DCEC;
  --brand-hover: #3177A0;
  --brand-pressed: #286285;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #141E24;
    --brand-ink: #D3E4EE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F4F8FB',
        100: '#E9F1F6',
        200: '#CEE2ED',
        300: '#A9CFE5',
        400: '#7EB6D8',
        500: '#539ECB',
        600: '#398bbc',
        700: '#2F749D',
        800: '#265D7D',
        900: '#1F455B',
        950: '#132B39',
        DEFAULT: '#398bbc',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F4F8FB,
  '100': #E9F1F6,
  '200': #CEE2ED,
  '300': #A9CFE5,
  '400': #7EB6D8,
  '500': #539ECB,
  '600': #398bbc,
  '700': #2F749D,
  '800': #265D7D,
  '900': #1F455B,
  '950': #132B39,
);
$brand-base: #398bbc;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F4F8FB", "$type": "color" },
      "100": { "$value": "#E9F1F6", "$type": "color" },
      "200": { "$value": "#CEE2ED", "$type": "color" },
      "300": { "$value": "#A9CFE5", "$type": "color" },
      "400": { "$value": "#7EB6D8", "$type": "color" },
      "500": { "$value": "#539ECB", "$type": "color" },
      "600": { "$value": "#398bbc", "$type": "color" },
      "700": { "$value": "#2F749D", "$type": "color" },
      "800": { "$value": "#265D7D", "$type": "color" },
      "900": { "$value": "#1F455B", "$type": "color" },
      "950": { "$value": "#132B39", "$type": "color" }
    },
    "brandInk": { "$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 #398bbc · 5.59:1
Use #000000AA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 3.75:1
AA fail · AA large pass · AAA fail
Aa
Black text · 5.59:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #398bbc as text scores 3.75:1 on white and 5.59:1 on black.
Best tinted ink on it, if plain black or white feels flat: #1E4862 at 2.59:1.

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
#337DA8 · 4.53:1
AA on white−5% L
#337DA8
The quick fox
#265D7D · 7.13:1
AAA on white−16% L
#265D7D
The quick fox
#398bbc · 5.59:1
AA on blackalready passes
#398bbc
The quick fox
#539ECB · 7.12:1
AAA on black+8% L
#539ECB

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #398BBC 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
#398bbc on white: 3.75:1
AA ✗ fail · AA-large · AAA
Aa
#398bbc on black: 5.59:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

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

NeutralRatioBoth directions
White3.75:1AaAa
Slate 503.59:1AaAa
Slate 1003.43:1AaAa
Slate 2003.05:1AaAa
Slate 3002.53:1AaAa
Slate 4001.46:1AaAa
Slate 5001.27:1AaAa
Slate 6002.02:1AaAa
Slate 7002.76:1AaAa
Slate 8003.90:1AaAa
Slate 9004.75:1AaAa
Black5.59:1AaAa
Colour vision deficiency
true color
protanopia · #748BBE
deuteranopia · #627EBB
tritanopia · #00979C

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. #398bbc 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.

#F4F8FB
#E9F1F6
#CEE2ED
#A9CFE5
#7EB6D8
#539ECB
#398bbc
#2F749D
#265D7D
#1F455B
#132B39
Base = 600Lightest = 50 · #F4F8FBDarkest = 950 · #132B39Text step on white = 700
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 0.027 238.5);
  --brand-100: oklch(0.94 0.043 238.5);
  --brand-200: oklch(0.88 0.065 238.5);
  --brand-300: oklch(0.80 0.084 238.5);
  --brand-400: oklch(0.72 0.100 238.5);
  --brand-500: oklch(0.64 0.108 238.5);
  --brand-600: oklch(0.56 0.108 238.5);
  --brand-700: oklch(0.48 0.102 238.5);
  --brand-800: oklch(0.40 0.091 238.5);
  --brand-900: oklch(0.32 0.076 238.5);
  --brand-950: oklch(0.24 0.060 238.5);
}

Colors that work with #398bbc

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#F4F8FA
Tinted page background
Border#C0DCEC
Hairlines and dividers
Muted text#4B7D9B
Captions on the surface
Accent#C14534
Second voice, not a rival
Dark variant#1E4862
Hover, pressed, headers
Light variant#EBF4F9
Selected rows, tints
Dark surface#141E24
Dark-mode background
Hover#3177A0
One step down in lightness
Pressed#286285
Two steps down
Disabled#A2B7C3
Chroma pulled out
Focus ring#3798D2
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 #398bbc

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
  • Brand accents, badges and data highlights
  • Chart series and data categories
Use with care
  • Small text on white — under 4.5:1
  • Full-page backgrounds — tiring over long sessions
  • 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 #1E4862
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.

trustedcalmcompetentcorporate

The default of institutions for a reason: blue is read as stable and safe across nearly every culture that has been surveyed.

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

It is also the most crowded hue on the web. Distinctiveness has to come from your other choices.

Reads as
  • FormalityMedium
  • EnergyMedium-high
  • Weight52/100
  • 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#BC6A39
Analogous left#39BCAB
Analogous right#394ABC
Split-complement 1#BC394A
Split-complement 2#BCAB39
Triadic 1#BC398B
Triadic 2#8BBC39
Tetradic#AB39BC
On the wheel
Base+30°−30°+120°+240°+180°202°

#398bbc sits at 202°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red22.4%
Green54.5%
Blue73.7%
R · 0–255
57
0x39
G · 0–255
139
0x8b
B · 0–255
188
0xbc

CMYK percentages

Cyan69.7%
Magenta26.1%
Yellow0.0%
Key (black)26.3%

Total ink coverage is 122%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#398bbc text on a black background

contrast 5.59:1

Card sample

#398bbc text on a white background

contrast 3.75:1

Card sample

#398bbc on grey

3.43:1

#398bbc on its own surface

3.51:1

#398bbc on its dark surface

4.51:1

CSS3 live lab

Text font color

The quick brown fox

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

Glowing headline

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

Soft neon halo

text-shadow: 0 0 14px rgba(57, 139, 188, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(57, 139, 188, 0.45);
Border & gradient
Gradient panel
border: 3px solid #398bbc;
background: linear-gradient(135deg, #398bbc, #3E39BC);
Gradient text

Gradient headline

background: linear-gradient(90deg, #398bbc, #5F39BC);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #398bbc;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #398bbc;
caret-color: #398bbc;
Left rule
Pull quote or callout
border-left: 4px solid #398bbc;
Ring + tint
Selected chip
background: #EBF4F9;
box-shadow: inset 0 0 0 2px #398bbc;
Conic badge
68%
background: conic-gradient(#398bbc 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #398bbc 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, 139, 188, 0.5)
rgb(57 139 188 / 50%)
#398bbc80
hsl(202 54% 48% / 50%)
color-mix(in srgb, #398bbc 50%, transparent)
Alpha8-digit hexFlat on white
10%#398bbc1a#EBF3F8
20%#398bbc33#D7E8F2
40%#398bbc66#B0D1E4
60%#398bbc99#88B9D7
80%#398bbccc#61A2C9

Gradients from #398bbc

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, #62A7D0, #398bbc 45%, #1E4862);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #398bbc, #4032A4);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #398bbc, #BC6A39);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #7AB4D7 0%, #398bbc 45%, #1E4862 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4F8FA, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #5BCDB5 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #4B50C8 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #1E4862 0%, transparent 65%), #398bbc;

Monochromatic scale

Palettes built from #398bbc

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.

#398bbc in the real world

Where a color in this family tends to land, and the interface roles it is usually asked to play.

Industries
TechnologyFinanceHealthcareEnterprise SaaS
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 5.59:1.

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.

#398bbc, answered

What color is #398bbc?

#398bbc is a balanced vivid blue, closest to Steel Blue (ΔE2000 4.2). It sits at 202° on the hue wheel with 54% saturation and 48% lightness, which reads as cool.

What is the RGB value of #398bbc?

rgb(57, 139, 188) — 57 red, 139 green and 188 blue out of 255, or 22.4% / 54.5% / 73.7% by channel.

What is #398bbc in HSL and HSV?

hsl(202, 54%, 48%) and hsv(202, 70%, 74%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #398bbc a light or a dark color?

It is a mid-tone. Relative luminance is 0.2297 and perceived brightness is 50%, so black text on it reaches 5.59:1.

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

Black. It scores 5.59:1 against #398bbc, versus 3.75:1 for white — AA at any size.

Is #398bbc accessible on a white background?

#398bbc on white scores 3.75:1, which only clears AA for large text — 18.66px bold or 24px regular and up. Darken it to #337DA8 to reach 4.5:1, or #265D7D for 7:1.

What is the complementary color of #398bbc?

#BC6A39 sits directly opposite on the wheel. Softer options are the split-complements #BC394A and #BCAB39, which give the same contrast with far less vibration.

What colors go well with #398bbc?

For interface work: #F4F8FA as the surface, #C0DCEC for borders, #4B7D9B for secondary text, #C14534 as an accent and #1E4862 for hover and pressed states. For a palette, the analogous pair #39BCAB and #394ABC stays calm, while #BC6A39 is the loudest partner.

What is #398bbc in CMYK for printing?

cmyk(70%, 26%, 0%, 26%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #398bbc warm or cool?

Cool — it scores 97 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #39BBBC; nudged cooler, #3172AB.

Which Tailwind color is closest to #398bbc?

The sky family — its 500 step is #0ea5e9, ΔE2000 8.9 away. That is a visible difference, so define #398bbc as a custom token rather than reaching for the built-in.

How do I use #398bbc in Tailwind CSS?

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

rgba(57, 139, 188, 0.5), or #398bbc80 in eight-digit hex. Over white that composites to #9CC5DE; over black, #1D465E.

Is #398bbc a web-safe color?

No. The nearest web-safe colour is #3399CC, ΔE2000 4.8 away. The palette only matters for legacy displays and some email clients now.

What does the color #398bbc mean?

As a blue, it reads trusted, calm, competent. The default of institutions for a reason: blue is read as stable and safe across nearly every culture that has been surveyed. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #398bbc?

The safest is same-hue elevation: linear-gradient(135deg, #62A7D0, #398bbc 45%, #1E4862). For more colour, a short hue run to #4032A4 keeps it rich without turning muddy.

Work with #398bbc in the Color Lab

Every tool opens with this colour already loaded.

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