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blue · cool

#537eb2

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

Token name suggestion: Signal Denim

RGB
83, 126, 178
HSL
213°, 38%, 51%
CMYK
53, 29, 0, 30
Luminance
0.1998

#537eb2 is a balanced soft blue, 213° on the wheel and 98/100 on the cool side. Put black text on it (5.00:1). As text it scores 4.20:1 on white — large text only. Nearest name is Steel Blue, nearest Tailwind family is blue.

hsl(213 38% 51%)rgb(83 126 178)Base step 600AA inkCool

At a glance

Every number on this page in one read: what #537eb2 is made of, how bright it looks, and which way it leans.

Hex
#537eb2
Hue
213°
blue
Saturation
38%
soft
Lightness
51%
balanced
Brightness
70%
HSV value
Perceived
48%
weighted brightness
Luminance
0.1998
WCAG relative
Temperature
Cool
98/100 cool
Color family
Blue
Tone
Soft
Best ink
Black
5.00:1
Closest name
Steel Blue
ΔE2000 3.5
Chroma
32.0
LCH, 0–130ish
OKLCH L
0.584
perceptual lightness
Tailwind
blue
500 · ΔE 6.7
Web-safe
#666699
nearest of 216
Where it sits
Hue213° of 360°
Saturation38%
Lightness51%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #537eb2.

Temperature
Warm ← → Cool98% 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
Red9%
Green75%
Blue16%

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

Every format

HEX#537eb2
HEX (8-digit)#537eb2ff
RGBrgb(83, 126, 178)
RGBArgba(83, 126, 178, 1)
HSLhsl(213, 38%, 51%)
HSV / HSBhsv(213, 53%, 70%)
HWBhwb(213 33% 30%)
CMYKcmyk(53%, 29%, 0%, 30%)
LABlab(51.8 0.4 -32.0)
LCHlch(51.8 32.0 270.7)
OKLCHoklch(0.584 0.094 253.9)
XYZ (D65)xyz(19.06, 19.97, 44.96)
Decimal5471922
Display P3color(display-p3 0.325 0.494 0.698)
Web-safe#666699

Copy-ready code

every platformclick to select
/* CSS */
color: #537eb2;
background-color: #537eb2;
/* CSS custom property */
--brand: #537eb2;
/* Tailwind (arbitrary) */
class="text-[#537eb2] bg-[#537eb2]"
/* SCSS */
$brand: #537eb2;
/* SwiftUI */
Color(red: 0.325, green: 0.494, blue: 0.698)
/* UIKit */
UIColor(red: 0.325, green: 0.494, blue: 0.698, alpha: 1)
/* Android XML */
<color name="brand">#537EB2</color>
/* Android Compose */
Color(0xFF537EB2)
/* Flutter */
Color(0xFF537EB2)
/* Python / OpenCV (BGR) */
(178, 126, 83)
/* Python / PIL (RGB) */
(83, 126, 178)
/* Java AWT */
new Color(83, 126, 178)
/* .NET */
Color.FromArgb(255, 83, 126, 178)
/* OpenGL / Unity (0–1) */
(0.3255f, 0.4941f, 0.6980f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{83,126,178}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #537eb2 85%, white);
border-color: color-mix(in oklab, #537eb2 40%, transparent);
/* theme-aware in one line */
color: light-dark(#273D58, #D5DFEC);
/* relative colour syntax */
--hover: hsl(from #537eb2 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: #EBEFF4;
  --brand-200: #D3DDE9;
  --brand-300: #B1C5DC;
  --brand-400: #8BA8CB;
  --brand-500: #648BBA;
  --brand-600: #537eb2;
  --brand-700: #3F628D;
  --brand-800: #324F71;
  --brand-900: #283B53;
  --brand-950: #192534;
  --brand: #537eb2;
  --brand-ink: #000000;
  --brand-surface: #F4F7FA;
  --brand-border: #C7D5E6;
  --brand-hover: #466D9C;
  --brand-pressed: #3B5B83;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #141B24;
    --brand-ink: #D5DFEC;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F5F7FA',
        100: '#EBEFF4',
        200: '#D3DDE9',
        300: '#B1C5DC',
        400: '#8BA8CB',
        500: '#648BBA',
        600: '#537eb2',
        700: '#3F628D',
        800: '#324F71',
        900: '#283B53',
        950: '#192534',
        DEFAULT: '#537eb2',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F5F7FA,
  '100': #EBEFF4,
  '200': #D3DDE9,
  '300': #B1C5DC,
  '400': #8BA8CB,
  '500': #648BBA,
  '600': #537eb2,
  '700': #3F628D,
  '800': #324F71,
  '900': #283B53,
  '950': #192534,
);
$brand-base: #537eb2;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F5F7FA", "$type": "color" },
      "100": { "$value": "#EBEFF4", "$type": "color" },
      "200": { "$value": "#D3DDE9", "$type": "color" },
      "300": { "$value": "#B1C5DC", "$type": "color" },
      "400": { "$value": "#8BA8CB", "$type": "color" },
      "500": { "$value": "#648BBA", "$type": "color" },
      "600": { "$value": "#537eb2", "$type": "color" },
      "700": { "$value": "#3F628D", "$type": "color" },
      "800": { "$value": "#324F71", "$type": "color" },
      "900": { "$value": "#283B53", "$type": "color" },
      "950": { "$value": "#192534", "$type": "color" }
    },
    "brandInk": { "$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 #537eb2 · 5.00:1
Use #000000AA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 4.20:1
AA fail · AA large pass · AAA fail
Aa
Black text · 5.00:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #537eb2 as text scores 4.20:1 on white and 5.00:1 on black.
Best tinted ink on it, if plain black or white feels flat: #273D58 at 2.64:1.

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
#4E79AD · 4.50:1
AA on white−2% L
#4E79AD
The quick fox
#395980 · 7.21:1
AAA on white−15% L
#395980
The quick fox
#537eb2 · 5.00:1
AA on blackalready passes
#537eb2
The quick fox
#7699C2 · 7.11:1
AAA on black+10% L
#7699C2

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #537EB2 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
#537eb2 on white: 4.20:1
AA ✗ fail · AA-large · AAA
Aa
#537eb2 on black: 5.00:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #537eb2 as text on that neutral, and that neutral as text on #537eb2.

NeutralRatioBoth directions
White4.20:1AaAa
Slate 504.02:1AaAa
Slate 1003.84:1AaAa
Slate 2003.41:1AaAa
Slate 3002.83:1AaAa
Slate 4001.64:1AaAa
Slate 5001.13:1AaAa
Slate 6001.80:1AaAa
Slate 7002.46:1AaAa
Slate 8003.48:1AaAa
Slate 9004.25:1AaAa
Black5.00:1AaAa
Colour vision deficiency
true color
protanopia · #6981B4
deuteranopia · #5D77B1
tritanopia · #1E8A90

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. #537eb2 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
#EBEFF4
#D3DDE9
#B1C5DC
#8BA8CB
#648BBA
#537eb2
#3F628D
#324F71
#283B53
#192534
Base = 600Lightest = 50 · #F5F7FADarkest = 950 · #192534Text 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 0.023 253.9);
  --brand-100: oklch(0.94 0.037 253.9);
  --brand-200: oklch(0.88 0.056 253.9);
  --brand-300: oklch(0.80 0.073 253.9);
  --brand-400: oklch(0.72 0.086 253.9);
  --brand-500: oklch(0.64 0.094 253.9);
  --brand-600: oklch(0.56 0.094 253.9);
  --brand-700: oklch(0.48 0.088 253.9);
  --brand-800: oklch(0.40 0.079 253.9);
  --brand-900: oklch(0.32 0.066 253.9);
  --brand-950: oklch(0.24 0.051 253.9);
}

Colors that work with #537eb2

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#F4F7FA
Tinted page background
Border#C7D5E6
Hairlines and dividers
Muted text#4B6F9B
Captions on the surface
Accent#B76D4E
Second voice, not a rival
Dark variant#273D58
Hover, pressed, headers
Light variant#EDF2F7
Selected rows, tints
Dark surface#141B24
Dark-mode background
Hover#466D9C
One step down in lightness
Pressed#3B5B83
Two steps down
Disabled#ACB9CA
Chroma pulled out
Focus ring#5688C4
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 #537eb2

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
  • Brand accents, badges and data highlights
  • Chart series and data categories
Use with care
  • Small text on white — under 4.5:1
  • 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 #273D58
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.

The muted chroma softens the association — it reads considered rather than loud, which suits long-form and data-heavy screens. 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
  • 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#B28753
Analogous left#53AEB2
Analogous right#5753B2
Split-complement 1#B25753
Split-complement 2#AEB253
Triadic 1#B2537E
Triadic 2#7EB253
Tetradic#B253AE
On the wheel
Base+30°−30°+120°+240°+180°213°

#537eb2 sits at 213°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red32.5%
Green49.4%
Blue69.8%
R · 0–255
83
0x53
G · 0–255
126
0x7e
B · 0–255
178
0xb2

CMYK percentages

Cyan53.4%
Magenta29.2%
Yellow0.0%
Key (black)30.2%

Total ink coverage is 113%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#537eb2 text on a black background

contrast 5.00:1

Card sample

#537eb2 text on a white background

contrast 4.20:1

Card sample

#537eb2 on grey

3.84:1

#537eb2 on its own surface

3.91:1

#537eb2 on its dark surface

4.12:1

CSS3 live lab

Text font color

The quick brown fox

color: #537eb2;
Background color
Panel with #537eb2 background
background-color: #537eb2;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #537eb2;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(83, 126, 178, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(83, 126, 178, 0.45);
Border & gradient
Gradient panel
border: 3px solid #537eb2;
background: linear-gradient(135deg, #537eb2, #6753B2);
Gradient text

Gradient headline

background: linear-gradient(90deg, #537eb2, #7F53B2);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #537eb2;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #537eb2;
caret-color: #537eb2;
Left rule
Pull quote or callout
border-left: 4px solid #537eb2;
Ring + tint
Selected chip
background: #EDF2F7;
box-shadow: inset 0 0 0 2px #537eb2;
Conic badge
68%
background: conic-gradient(#537eb2 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #537eb2 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(83, 126, 178, 0.5)
rgb(83 126 178 / 50%)
#537eb280
hsl(213 38% 51% / 50%)
color-mix(in srgb, #537eb2 50%, transparent)
Alpha8-digit hexFlat on white
10%#537eb21a#EEF2F7
20%#537eb233#DDE5F0
40%#537eb266#BACBE0
60%#537eb299#98B2D1
80%#537eb2cc#7598C1

Gradients from #537eb2

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, #7D9EC5, #537eb2 45%, #273D58);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #537eb2, #61479F);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #537eb2, #B28753);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #92AECE 0%, #537eb2 45%, #273D58 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%, #76C2BF 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #7368BC 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #273D58 0%, transparent 65%), #537eb2;

Monochromatic scale

Palettes built from #537eb2

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.

#537eb2 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 5.00:1.

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.

#537eb2, answered

What color is #537eb2?

#537eb2 is a balanced soft blue, closest to Steel Blue (ΔE2000 3.5). It sits at 213° on the hue wheel with 38% saturation and 51% lightness, which reads as cool.

What is the RGB value of #537eb2?

rgb(83, 126, 178) — 83 red, 126 green and 178 blue out of 255, or 32.5% / 49.4% / 69.8% by channel.

What is #537eb2 in HSL and HSV?

hsl(213, 38%, 51%) and hsv(213, 53%, 70%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #537eb2 a light or a dark color?

It is a mid-tone. Relative luminance is 0.1998 and perceived brightness is 48%, so black text on it reaches 5.00:1.

Should I use black or white text on #537eb2?

Black. It scores 5.00:1 against #537eb2, versus 4.20:1 for white — AA at any size.

Is #537eb2 accessible on a white background?

#537eb2 on white scores 4.20:1, which only clears AA for large text — 18.66px bold or 24px regular and up. Darken it to #4E79AD to reach 4.5:1, or #395980 for 7:1.

What is the complementary color of #537eb2?

#B28753 sits directly opposite on the wheel. Softer options are the split-complements #B25753 and #AEB253, which give the same contrast with far less vibration.

What colors go well with #537eb2?

For interface work: #F4F7FA as the surface, #C7D5E6 for borders, #4B6F9B for secondary text, #B76D4E as an accent and #273D58 for hover and pressed states. For a palette, the analogous pair #53AEB2 and #5753B2 stays calm, while #B28753 is the loudest partner.

What is #537eb2 in CMYK for printing?

cmyk(53%, 29%, 0%, 30%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #537eb2 warm or cool?

Cool — it scores 98 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #535BB2; nudged cooler, #4672A5.

Which Tailwind color is closest to #537eb2?

The blue family — its 500 step is #3b82f6, ΔE2000 6.7 away. That is a visible difference, so define #537eb2 as a custom token rather than reaching for the built-in.

How do I use #537eb2 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#537eb2] or text-[#537eb2], 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 #537eb2 with 50% opacity?

rgba(83, 126, 178, 0.5), or #537eb280 in eight-digit hex. Over white that composites to #A9BFD9; over black, #2A3F59.

Is #537eb2 a web-safe color?

No. The nearest web-safe colour is #666699, ΔE2000 13.3 away. The palette only matters for legacy displays and some email clients now.

What does the color #537eb2 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 moderate chroma the association is present but not shouted.

What gradient works with #537eb2?

The safest is same-hue elevation: linear-gradient(135deg, #7D9EC5, #537eb2 45%, #273D58). For more colour, a short hue run to #61479F keeps it rich without turning muddy.

Work with #537eb2 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #537eb2 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.