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blue · cool

#36588f

a dark, vivid blue · cool · closest name: Royal Blue

Token name suggestion: Slate Harbour

RGB
54, 88, 143
HSL
217°, 45%, 39%
CMYK
62, 39, 0, 44
Luminance
0.0975

#36588f is a dark vivid blue, 217° on the wheel and 96/100 on the cool side. Put white text on it (7.12:1). As text it scores 7.12:1 on white — safe at any size. Nearest name is Royal Blue, nearest Tailwind family is slate.

hsl(217 45% 39%)rgb(54 88 143)Base step 700AAA inkCool

At a glance

Every number on this page in one read: what #36588f is made of, how bright it looks, and which way it leans.

Hex
#36588f
Hue
217°
blue
Saturation
45%
vivid
Lightness
39%
dark
Brightness
56%
HSV value
Perceived
35%
weighted brightness
Luminance
0.0975
WCAG relative
Temperature
Cool
96/100 cool
Color family
Blue
Tone
Vivid
Best ink
White
7.12:1
Closest name
Royal Blue
ΔE2000 11.8
Chroma
34.6
LCH, 0–130ish
OKLCH L
0.462
perceptual lightness
Tailwind
slate
500 · ΔE 12.8
Web-safe
#336699
nearest of 216
Where it sits
Hue217° of 360°
Saturation45%
Lightness39%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #36588f.

Temperature
Warm ← → Cool96% 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
Red8%
Green72%
Blue20%

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

Every format

HEX#36588f
HEX (8-digit)#36588fff
RGBrgb(54, 88, 143)
RGBArgba(54, 88, 143, 1)
HSLhsl(217, 45%, 39%)
HSV / HSBhsv(217, 62%, 56%)
HWBhwb(217 21% 44%)
CMYKcmyk(62%, 39%, 0%, 44%)
LABlab(37.4 5.7 -34.1)
LCHlch(37.4 34.6 279.5)
OKLCHoklch(0.462 0.099 259.6)
XYZ (D65)xyz(9.97, 9.75, 27.34)
Decimal3561615
Display P3color(display-p3 0.212 0.345 0.561)
Web-safe#336699

Copy-ready code

every platformclick to select
/* CSS */
color: #36588f;
background-color: #36588f;
/* CSS custom property */
--brand: #36588f;
/* Tailwind (arbitrary) */
class="text-[#36588f] bg-[#36588f]"
/* SCSS */
$brand: #36588f;
/* SwiftUI */
Color(red: 0.212, green: 0.345, blue: 0.561)
/* UIKit */
UIColor(red: 0.212, green: 0.345, blue: 0.561, alpha: 1)
/* Android XML */
<color name="brand">#36588F</color>
/* Android Compose */
Color(0xFF36588F)
/* Flutter */
Color(0xFF36588F)
/* Python / OpenCV (BGR) */
(143, 88, 54)
/* Python / PIL (RGB) */
(54, 88, 143)
/* Java AWT */
new Color(54, 88, 143)
/* .NET */
Color.FromArgb(255, 54, 88, 143)
/* OpenGL / Unity (0–1) */
(0.2118f, 0.3451f, 0.5608f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{54,88,143}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #36588f 85%, white);
border-color: color-mix(in oklab, #36588f 40%, transparent);
/* theme-aware in one line */
color: light-dark(#23395D, #D3DDEE);
/* relative colour syntax */
--hover: hsl(from #36588f 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: #EAEEF5;
  --brand-200: #D1DBEB;
  --brand-300: #AEC1E0;
  --brand-400: #85A2D1;
  --brand-500: #5C83C2;
  --brand-600: #436DB2;
  --brand-700: #36588f;
  --brand-800: #2D4976;
  --brand-900: #243757;
  --brand-950: #162236;
  --brand: #36588f;
  --brand-ink: #ffffff;
  --brand-surface: #F4F7FA;
  --brand-border: #C4D2E9;
  --brand-hover: #2C4875;
  --brand-pressed: #22385B;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #141A24;
    --brand-ink: #D3DDEE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F5F7FA',
        100: '#EAEEF5',
        200: '#D1DBEB',
        300: '#AEC1E0',
        400: '#85A2D1',
        500: '#5C83C2',
        600: '#436DB2',
        700: '#36588f',
        800: '#2D4976',
        900: '#243757',
        950: '#162236',
        DEFAULT: '#36588f',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F5F7FA,
  '100': #EAEEF5,
  '200': #D1DBEB,
  '300': #AEC1E0,
  '400': #85A2D1,
  '500': #5C83C2,
  '600': #436DB2,
  '700': #36588f,
  '800': #2D4976,
  '900': #243757,
  '950': #162236,
);
$brand-base: #36588f;
$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": "#EAEEF5", "$type": "color" },
      "200": { "$value": "#D1DBEB", "$type": "color" },
      "300": { "$value": "#AEC1E0", "$type": "color" },
      "400": { "$value": "#85A2D1", "$type": "color" },
      "500": { "$value": "#5C83C2", "$type": "color" },
      "600": { "$value": "#436DB2", "$type": "color" },
      "700": { "$value": "#36588f", "$type": "color" },
      "800": { "$value": "#2D4976", "$type": "color" },
      "900": { "$value": "#243757", "$type": "color" },
      "950": { "$value": "#162236", "$type": "color" }
    },
    "brandInk": { "$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 #36588f · 7.12:1
Use #ffffffAAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 7.12:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 2.95:1
AA fail · AA large fail · AAA fail
Reading the other direction: #36588f as text scores 7.12:1 on white and 2.95:1 on black.
Best tinted ink on it, if plain black or white feels flat: #ECF1F8 at 6.27:1.

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
#36588f · 7.12:1
AA on whitealready passes
#36588f
The quick fox
#36588f · 7.12:1
AAA on whitealready passes
#36588f
The quick fox
#4C76BB · 4.62:1
AA on black+13% L
#4C76BB
The quick fox
#7898CC · 7.16:1
AAA on black+25% L
#7898CC

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #36588F 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
#36588f on white: 7.12:1
AA ✓ pass · AA-large · AAA
Aa
#36588f on black: 2.95:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #36588f as text on that neutral, and that neutral as text on #36588f.

NeutralRatioBoth directions
White7.12:1AaAa
Slate 506.81:1AaAa
Slate 1006.50:1AaAa
Slate 2005.78:1AaAa
Slate 3004.80:1AaAa
Slate 4002.78:1AaAa
Slate 5001.50:1AaAa
Slate 6001.06:1AaAa
Slate 7001.45:1AaAa
Slate 8002.05:1AaAa
Slate 9002.51:1AaAa
Black2.95:1AaAa
Colour vision deficiency
true color
protanopia · #415C91
deuteranopia · #34548E
tritanopia · #00646C

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. #36588f 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.

#F5F7FA
#EAEEF5
#D1DBEB
#AEC1E0
#85A2D1
#5C83C2
#436DB2
#36588f
#2D4976
#243757
#162236
Base = 700Lightest = 50 · #F5F7FADarkest = 950 · #162236Text 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 0.025 259.6);
  --brand-100: oklch(0.94 0.039 259.6);
  --brand-200: oklch(0.88 0.059 259.6);
  --brand-300: oklch(0.80 0.077 259.6);
  --brand-400: oklch(0.72 0.091 259.6);
  --brand-500: oklch(0.64 0.099 259.6);
  --brand-600: oklch(0.56 0.099 259.6);
  --brand-700: oklch(0.48 0.093 259.6);
  --brand-800: oklch(0.40 0.083 259.6);
  --brand-900: oklch(0.32 0.069 259.6);
  --brand-950: oklch(0.24 0.054 259.6);
}

Colors that work with #36588f

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#C4D2E9
Hairlines and dividers
Muted text#4B699B
Captions on the surface
Accent#935632
Second voice, not a rival
Dark variant#23395D
Hover, pressed, headers
Light variant#ECF1F8
Selected rows, tints
Dark surface#141A24
Dark-mode background
Hover#2C4875
One step down in lightness
Pressed#22385B
Two steps down
Disabled#8495B1
Chroma pulled out
Focus ring#315EA9
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 #36588f

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

Works well for
  • Body text and links on white
  • 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
  • Text on black or near-black surfaces
  • Full-page backgrounds — tiring over long sessions
  • Black text placed on it
  • 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 low lightness adds weight and formality.

Worth knowing

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

Reads as
  • FormalityHigh
  • EnergyMedium-high
  • 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#8F6D36
Analogous left#36848F
Analogous right#40368F
Split-complement 1#8F4036
Split-complement 2#848F36
Triadic 1#8F3658
Triadic 2#588F36
Tetradic#8F3684
On the wheel
Base+30°−30°+120°+240°+180°217°

#36588f sits at 217°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red21.2%
Green34.5%
Blue56.1%
R · 0–255
54
0x36
G · 0–255
88
0x58
B · 0–255
143
0x8f

CMYK percentages

Cyan62.2%
Magenta38.5%
Yellow0.0%
Key (black)43.9%

Total ink coverage is 145%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#36588f text on a black background

contrast 2.95:1

Card sample

#36588f text on a white background

contrast 7.12:1

Card sample

#36588f on grey

6.50:1

#36588f on its own surface

6.62:1

#36588f on its dark surface

2.45:1

CSS3 live lab

Text font color

The quick brown fox

color: #36588f;
Background color
Panel with #36588f background
background-color: #36588f;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #36588f;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(54, 88, 143, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(54, 88, 143, 0.45);
Border & gradient
Gradient panel
border: 3px solid #36588f;
background: linear-gradient(135deg, #36588f, #4F368F);
Gradient text

Gradient headline

background: linear-gradient(90deg, #36588f, #66368F);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #36588f;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #36588f;
caret-color: #36588f;
Left rule
Pull quote or callout
border-left: 4px solid #36588f;
Ring + tint
Selected chip
background: #ECF1F8;
box-shadow: inset 0 0 0 2px #36588f;
Conic badge
68%
background: conic-gradient(#36588f 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #36588f 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(54, 88, 143, 0.5)
rgb(54 88 143 / 50%)
#36588f80
hsl(217 45% 39% / 50%)
color-mix(in srgb, #36588f 50%, transparent)
Alpha8-digit hexFlat on white
10%#36588f1a#EBEEF4
20%#36588f33#D7DEE9
40%#36588f66#AFBCD2
60%#36588f99#869BBC
80%#36588fcc#5E79A5

Gradients from #36588f

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, #4874BA, #36588f 45%, #23395D);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #36588f, #492E79);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #36588f, #8F6D36);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #5E84C2 0%, #36588f 45%, #23395D 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%, #44B0B4 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #533EA5 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #23395D 0%, transparent 65%), #36588f;

Monochromatic scale

Palettes built from #36588f

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.

#36588f 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

Too dim on dark surfaces at 2.95:1 — lift it to #4C76BB for body text, or reserve it for fills.

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.

#36588f, answered

What color is #36588f?

#36588f is a dark vivid blue, closest to Royal Blue (ΔE2000 11.8). It sits at 217° on the hue wheel with 45% saturation and 39% lightness, which reads as cool.

What is the RGB value of #36588f?

rgb(54, 88, 143) — 54 red, 88 green and 143 blue out of 255, or 21.2% / 34.5% / 56.1% by channel.

What is #36588f in HSL and HSV?

hsl(217, 45%, 39%) and hsv(217, 62%, 56%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #36588f a light or a dark color?

It is a dark color. Relative luminance is 0.0975 and perceived brightness is 35%, so white text on it reaches 7.12:1.

Should I use black or white text on #36588f?

White. It scores 7.12:1 against #36588f, versus 2.95:1 for black — AAA at any size.

Is #36588f accessible on a white background?

#36588f on white scores 7.12:1, which clears AAA at every size.

What is the complementary color of #36588f?

#8F6D36 sits directly opposite on the wheel. Softer options are the split-complements #8F4036 and #848F36, which give the same contrast with far less vibration.

What colors go well with #36588f?

For interface work: #F4F7FA as the surface, #C4D2E9 for borders, #4B699B for secondary text, #935632 as an accent and #23395D for hover and pressed states. For a palette, the analogous pair #36848F and #40368F stays calm, while #8F6D36 is the loudest partner.

What is #36588f in CMYK for printing?

cmyk(62%, 39%, 0%, 44%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #36588f warm or cool?

Cool — it scores 96 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #36378F; nudged cooler, #2D517E.

Which Tailwind color is closest to #36588f?

The slate family — its 500 step is #64748b, ΔE2000 12.8 away. That is a visible difference, so define #36588f as a custom token rather than reaching for the built-in.

How do I use #36588f in Tailwind CSS?

Inline it as an arbitrary value with bg-[#36588f] or text-[#36588f], 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 #36588f with 50% opacity?

rgba(54, 88, 143, 0.5), or #36588f80 in eight-digit hex. Over white that composites to #9BACC7; over black, #1B2C48.

Is #36588f a web-safe color?

No. The nearest web-safe colour is #336699, ΔE2000 5.7 away. The palette only matters for legacy displays and some email clients now.

What does the color #36588f 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 #36588f?

The safest is same-hue elevation: linear-gradient(135deg, #4874BA, #36588f 45%, #23395D). For more colour, a short hue run to #492E79 keeps it rich without turning muddy.

Work with #36588f in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #36588f at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.