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blue · cool

#4178ad

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

Token name suggestion: Studio Harbour

RGB
65, 120, 173
HSL
209°, 45%, 47%
CMYK
62, 31, 0, 32
Luminance
0.1757

#4178ad is a balanced vivid blue, 209° on the wheel and 100/100 on the cool side. Put white text on it (4.65:1). As text it scores 4.65:1 on white — safe at any size. Nearest name is Steel Blue, nearest Tailwind family is blue.

hsl(209 45% 47%)rgb(65 120 173)Base step 600AA inkCool

At a glance

Every number on this page in one read: what #4178ad is made of, how bright it looks, and which way it leans.

Hex
#4178ad
Hue
209°
blue
Saturation
45%
vivid
Lightness
47%
balanced
Brightness
68%
HSV value
Perceived
45%
weighted brightness
Luminance
0.1757
WCAG relative
Temperature
Cool
100/100 cool
Color family
Blue
Tone
Vivid
Best ink
White
4.65:1
Closest name
Steel Blue
ΔE2000 3.9
Chroma
33.7
LCH, 0–130ish
OKLCH L
0.559
perceptual lightness
Tailwind
blue
500 · ΔE 8.5
Web-safe
#336699
nearest of 216
Where it sits
Hue209° of 360°
Saturation45%
Lightness47%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #4178ad.

Temperature
Warm ← → Cool100% 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
Red6%
Green76%
Blue17%

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

Every format

HEX#4178ad
HEX (8-digit)#4178adff
RGBrgb(65, 120, 173)
RGBArgba(65, 120, 173, 1)
HSLhsl(209, 45%, 47%)
HSV / HSBhsv(209, 62%, 68%)
HWBhwb(209 25% 32%)
CMYKcmyk(62%, 31%, 0%, 32%)
LABlab(49.0 -1.5 -33.6)
LCHlch(49.0 33.7 267.5)
OKLCHoklch(0.559 0.101 249.3)
XYZ (D65)xyz(16.44, 17.57, 42.05)
Decimal4290733
Display P3color(display-p3 0.255 0.471 0.678)
Web-safe#336699

Copy-ready code

every platformclick to select
/* CSS */
color: #4178ad;
background-color: #4178ad;
/* CSS custom property */
--brand: #4178ad;
/* Tailwind (arbitrary) */
class="text-[#4178ad] bg-[#4178ad]"
/* SCSS */
$brand: #4178ad;
/* SwiftUI */
Color(red: 0.255, green: 0.471, blue: 0.678)
/* UIKit */
UIColor(red: 0.255, green: 0.471, blue: 0.678, alpha: 1)
/* Android XML */
<color name="brand">#4178AD</color>
/* Android Compose */
Color(0xFF4178AD)
/* Flutter */
Color(0xFF4178AD)
/* Python / OpenCV (BGR) */
(173, 120, 65)
/* Python / PIL (RGB) */
(65, 120, 173)
/* Java AWT */
new Color(65, 120, 173)
/* .NET */
Color.FromArgb(255, 65, 120, 173)
/* OpenGL / Unity (0–1) */
(0.2549f, 0.4706f, 0.6784f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{65,120,173}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #4178ad 85%, white);
border-color: color-mix(in oklab, #4178ad 40%, transparent);
/* theme-aware in one line */
color: light-dark(#23405D, #D3E1EE);
/* relative colour syntax */
--hover: hsl(from #4178ad 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: #F5F7FA;
  --brand-100: #EAF0F5;
  --brand-200: #D1DEEB;
  --brand-300: #ADC7E0;
  --brand-400: #85ACD1;
  --brand-500: #5C90C2;
  --brand-600: #4178ad;
  --brand-700: #386794;
  --brand-800: #2D5277;
  --brand-900: #243E57;
  --brand-950: #162736;
  --brand: #4178ad;
  --brand-ink: #ffffff;
  --brand-surface: #F4F7FA;
  --brand-border: #C4D7E9;
  --brand-hover: #376693;
  --brand-pressed: #2E5479;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #141C24;
    --brand-ink: #D3E1EE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F5F7FA',
        100: '#EAF0F5',
        200: '#D1DEEB',
        300: '#ADC7E0',
        400: '#85ACD1',
        500: '#5C90C2',
        600: '#4178ad',
        700: '#386794',
        800: '#2D5277',
        900: '#243E57',
        950: '#162736',
        DEFAULT: '#4178ad',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F5F7FA,
  '100': #EAF0F5,
  '200': #D1DEEB,
  '300': #ADC7E0,
  '400': #85ACD1,
  '500': #5C90C2,
  '600': #4178ad,
  '700': #386794,
  '800': #2D5277,
  '900': #243E57,
  '950': #162736,
);
$brand-base: #4178ad;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F5F7FA", "$type": "color" },
      "100": { "$value": "#EAF0F5", "$type": "color" },
      "200": { "$value": "#D1DEEB", "$type": "color" },
      "300": { "$value": "#ADC7E0", "$type": "color" },
      "400": { "$value": "#85ACD1", "$type": "color" },
      "500": { "$value": "#5C90C2", "$type": "color" },
      "600": { "$value": "#4178ad", "$type": "color" },
      "700": { "$value": "#386794", "$type": "color" },
      "800": { "$value": "#2D5277", "$type": "color" },
      "900": { "$value": "#243E57", "$type": "color" },
      "950": { "$value": "#162736", "$type": "color" }
    },
    "brandInk": { "$value": "#ffffff", "$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#ffffff on #4178ad · 4.65:1
Use #ffffffAA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 4.65:1 · recommended
AA pass · AA large pass · AAA fail
Aa
Black text · 4.51:1
AA pass · AA large pass · AAA fail
Reading the other direction: #4178ad as text scores 4.65:1 on white and 4.51:1 on black.
Best tinted ink on it, if plain black or white feels flat: #ECF2F8 at 4.12:1.

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
#4178ad · 4.65:1
AA on whitealready passes
#4178ad
The quick fox
#325C84 · 7.00:1
AAA on white−11% L
#325C84
The quick fox
#4178ad · 4.51:1
AA on blackalready passes
#4178ad
The quick fox
#6D9CC8 · 7.24:1
AAA on black+14% L
#6D9CC8

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #4178AD 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
#4178ad on white: 4.65:1
AA ✓ pass · AA-large · AAA
Aa
#4178ad on black: 4.51:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #4178ad as text on that neutral, and that neutral as text on #4178ad.

NeutralRatioBoth directions
White4.65:1AaAa
Slate 504.45:1AaAa
Slate 1004.25:1AaAa
Slate 2003.77:1AaAa
Slate 3003.13:1AaAa
Slate 4001.81:1AaAa
Slate 5001.02:1AaAa
Slate 6001.63:1AaAa
Slate 7002.23:1AaAa
Slate 8003.15:1AaAa
Slate 9003.84:1AaAa
Black4.51:1AaAa
Colour vision deficiency
true color
protanopia · #617AAF
deuteranopia · #5370AC
tritanopia · #00848B

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. #4178ad 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.

#F5F7FA
#EAF0F5
#D1DEEB
#ADC7E0
#85ACD1
#5C90C2
#4178ad
#386794
#2D5277
#243E57
#162736
Base = 600Lightest = 50 · #F5F7FADarkest = 950 · #162736Text step on white = 600
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 0.025 249.3);
  --brand-100: oklch(0.94 0.041 249.3);
  --brand-200: oklch(0.88 0.061 249.3);
  --brand-300: oklch(0.80 0.079 249.3);
  --brand-400: oklch(0.72 0.093 249.3);
  --brand-500: oklch(0.64 0.101 249.3);
  --brand-600: oklch(0.56 0.101 249.3);
  --brand-700: oklch(0.48 0.095 249.3);
  --brand-800: oklch(0.40 0.085 249.3);
  --brand-900: oklch(0.32 0.071 249.3);
  --brand-950: oklch(0.24 0.056 249.3);
}

Colors that work with #4178ad

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#ffffff
White wins here
Surface#F4F7FA
Tinted page background
Border#C4D7E9
Hairlines and dividers
Muted text#4B749B
Captions on the surface
Accent#B2583C
Second voice, not a rival
Dark variant#23405D
Hover, pressed, headers
Light variant#ECF2F8
Selected rows, tints
Dark surface#141C24
Dark-mode background
Hover#376693
One step down in lightness
Pressed#2E5479
Two steps down
Disabled#9EB0C1
Chroma pulled out
Focus ring#3C83C7
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 #4178ad

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

Works well for
  • Body text and links 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
  • Full-page backgrounds — tiring over long sessions
  • Pairing with a same-lightness hue — edges vibrate
Minimum size as text on white
Any size
Safe as a fill behind white type
Yes
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
  • Weight53/100
  • 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#AD7641
Analogous left#41ADAC
Analogous right#4142AD
Split-complement 1#AD4142
Split-complement 2#ADAC41
Triadic 1#AD4178
Triadic 2#78AD41
Tetradic#AC41AD
On the wheel
Base+30°−30°+120°+240°+180°209°

#4178ad sits at 209°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red25.5%
Green47.1%
Blue67.8%
R · 0–255
65
0x41
G · 0–255
120
0x78
B · 0–255
173
0xad

CMYK percentages

Cyan62.4%
Magenta30.6%
Yellow0.0%
Key (black)32.2%

Total ink coverage is 125%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#4178ad text on a black background

contrast 4.51:1

Card sample

#4178ad text on a white background

contrast 4.65:1

Card sample

#4178ad on grey

4.25:1

#4178ad on its own surface

4.33:1

#4178ad on its dark surface

3.70:1

CSS3 live lab

Text font color

The quick brown fox

color: #4178ad;
Background color
Panel with #4178ad background
background-color: #4178ad;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #4178ad;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(65, 120, 173, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(65, 120, 173, 0.45);
Border & gradient
Gradient panel
border: 3px solid #4178ad;
background: linear-gradient(135deg, #4178ad, #5241AD);
Gradient text

Gradient headline

background: linear-gradient(90deg, #4178ad, #6D41AD);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #4178ad;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #4178ad;
caret-color: #4178ad;
Left rule
Pull quote or callout
border-left: 4px solid #4178ad;
Ring + tint
Selected chip
background: #ECF2F8;
box-shadow: inset 0 0 0 2px #4178ad;
Conic badge
68%
background: conic-gradient(#4178ad 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #4178ad 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(65, 120, 173, 0.5)
rgb(65 120 173 / 50%)
#4178ad80
hsl(209 45% 47% / 50%)
color-mix(in srgb, #4178ad 50%, transparent)
Alpha8-digit hexFlat on white
10%#4178ad1a#ECF2F7
20%#4178ad33#D9E4EF
40%#4178ad66#B3C9DE
60%#4178ad99#8DAECE
80%#4178adcc#6793BD

Gradients from #4178ad

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, #6697C5, #4178ad 45%, #23405D);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #4178ad, #4F3997);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #4178ad, #AD7641);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #7CA6CE 0%, #4178ad 45%, #23405D 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4F7FA, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #5EC3B9 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #5850BD 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #23405D 0%, transparent 65%), #4178ad;

Monochromatic scale

Palettes built from #4178ad

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.

#4178ad 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 4.51:1.

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.

#4178ad, answered

What color is #4178ad?

#4178ad is a balanced vivid blue, closest to Steel Blue (ΔE2000 3.9). It sits at 209° on the hue wheel with 45% saturation and 47% lightness, which reads as cool.

What is the RGB value of #4178ad?

rgb(65, 120, 173) — 65 red, 120 green and 173 blue out of 255, or 25.5% / 47.1% / 67.8% by channel.

What is #4178ad in HSL and HSV?

hsl(209, 45%, 47%) and hsv(209, 62%, 68%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #4178ad a light or a dark color?

It is a dark color. Relative luminance is 0.1757 and perceived brightness is 45%, so white text on it reaches 4.65:1.

Should I use black or white text on #4178ad?

White. It scores 4.65:1 against #4178ad, versus 4.51:1 for black — AA at any size.

Is #4178ad accessible on a white background?

#4178ad on white scores 4.65:1, which clears AA at every size but not AAA.

What is the complementary color of #4178ad?

#AD7641 sits directly opposite on the wheel. Softer options are the split-complements #AD4142 and #ADAC41, which give the same contrast with far less vibration.

What colors go well with #4178ad?

For interface work: #F4F7FA as the surface, #C4D7E9 for borders, #4B749B for secondary text, #B2583C as an accent and #23405D for hover and pressed states. For a palette, the analogous pair #41ADAC and #4142AD stays calm, while #AD7641 is the loudest partner.

What is #4178ad in CMYK for printing?

cmyk(62%, 31%, 0%, 32%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #4178ad warm or cool?

Cool — it scores 100 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #4151AD; nudged cooler, #38699D.

Which Tailwind color is closest to #4178ad?

The blue family — its 500 step is #3b82f6, ΔE2000 8.5 away. That is a visible difference, so define #4178ad as a custom token rather than reaching for the built-in.

How do I use #4178ad in Tailwind CSS?

Inline it as an arbitrary value with bg-[#4178ad] or text-[#4178ad], 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 #4178ad with 50% opacity?

rgba(65, 120, 173, 0.5), or #4178ad80 in eight-digit hex. Over white that composites to #A0BCD6; over black, #213C57.

Is #4178ad a web-safe color?

No. The nearest web-safe colour is #336699, ΔE2000 6.8 away. The palette only matters for legacy displays and some email clients now.

What does the color #4178ad 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 #4178ad?

The safest is same-hue elevation: linear-gradient(135deg, #6697C5, #4178ad 45%, #23405D). For more colour, a short hue run to #4F3997 keeps it rich without turning muddy.

Work with #4178ad in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #4178ad at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.