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blue · cool

#213959

a deep, vivid blue · cool · closest name: Dark Slate Blue

Token name suggestion: Abyss Cobalt

RGB
33, 57, 89
HSL
214°, 46%, 24%
CMYK
63, 36, 0, 65
Luminance
0.0397

#213959 is a deep vivid blue, 214° on the wheel and 98/100 on the cool side. Put white text on it (11.70:1). As text it scores 11.70:1 on white — safe at any size. Nearest name is Dark Slate Blue, nearest Tailwind family is slate.

hsl(214 46% 24%)rgb(33 57 89)Base step 900AAA inkCool

At a glance

Every number on this page in one read: what #213959 is made of, how bright it looks, and which way it leans.

Hex
#213959
Hue
214°
blue
Saturation
46%
vivid
Lightness
24%
deep
Brightness
35%
HSV value
Perceived
22%
weighted brightness
Luminance
0.0397
WCAG relative
Temperature
Cool
98/100 cool
Color family
Blue
Tone
Vivid
Best ink
White
11.70:1
Closest name
Dark Slate Blue
ΔE2000 11.2
Chroma
22.1
LCH, 0–130ish
OKLCH L
0.342
perceptual lightness
Tailwind
slate
500 · ΔE 21
Web-safe
#333366
nearest of 216
Where it sits
Hue214° of 360°
Saturation46%
Lightness24%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #213959.

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
Red8%
Green74%
Blue18%

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

Every format

HEX#213959
HEX (8-digit)#213959ff
RGBrgb(33, 57, 89)
RGBArgba(33, 57, 89, 1)
HSLhsl(214, 46%, 24%)
HSV / HSBhsv(214, 63%, 35%)
HWBhwb(214 13% 65%)
CMYKcmyk(63%, 36%, 0%, 65%)
LABlab(23.6 1.8 -22.0)
LCHlch(23.6 22.1 274.6)
OKLCHoklch(0.342 0.064 256.1)
XYZ (D65)xyz(3.89, 3.97, 10.01)
Decimal2177369
Display P3color(display-p3 0.129 0.224 0.349)
Web-safe#333366

Copy-ready code

every platformclick to select
/* CSS */
color: #213959;
background-color: #213959;
/* CSS custom property */
--brand: #213959;
/* Tailwind (arbitrary) */
class="text-[#213959] bg-[#213959]"
/* SCSS */
$brand: #213959;
/* SwiftUI */
Color(red: 0.129, green: 0.224, blue: 0.349)
/* UIKit */
UIColor(red: 0.129, green: 0.224, blue: 0.349, alpha: 1)
/* Android XML */
<color name="brand">#213959</color>
/* Android Compose */
Color(0xFF213959)
/* Flutter */
Color(0xFF213959)
/* Python / OpenCV (BGR) */
(89, 57, 33)
/* Python / PIL (RGB) */
(33, 57, 89)
/* Java AWT */
new Color(33, 57, 89)
/* .NET */
Color.FromArgb(255, 33, 57, 89)
/* OpenGL / Unity (0–1) */
(0.1294f, 0.2235f, 0.3490f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{33,57,89}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #213959 85%, white);
border-color: color-mix(in oklab, #213959 40%, transparent);
/* theme-aware in one line */
color: light-dark(#223C5D, #D3DEEE);
/* relative colour syntax */
--hover: hsl(from #213959 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: #EAEFF5;
  --brand-200: #D0DCEB;
  --brand-300: #ADC3E1;
  --brand-400: #84A5D1;
  --brand-500: #5B87C2;
  --brand-600: #4272B3;
  --brand-700: #375F95;
  --brand-800: #2C4C77;
  --brand-900: #213959;
  --brand-950: #162436;
  --brand: #213959;
  --brand-ink: #ffffff;
  --brand-surface: #F4F7FA;
  --brand-border: #C3D4E9;
  --brand-hover: #17283F;
  --brand-pressed: #0E1825;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #141B24;
    --brand-ink: #D3DEEE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F5F7FA',
        100: '#EAEFF5',
        200: '#D0DCEB',
        300: '#ADC3E1',
        400: '#84A5D1',
        500: '#5B87C2',
        600: '#4272B3',
        700: '#375F95',
        800: '#2C4C77',
        900: '#213959',
        950: '#162436',
        DEFAULT: '#213959',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F5F7FA,
  '100': #EAEFF5,
  '200': #D0DCEB,
  '300': #ADC3E1,
  '400': #84A5D1,
  '500': #5B87C2,
  '600': #4272B3,
  '700': #375F95,
  '800': #2C4C77,
  '900': #213959,
  '950': #162436,
);
$brand-base: #213959;
$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": "#EAEFF5", "$type": "color" },
      "200": { "$value": "#D0DCEB", "$type": "color" },
      "300": { "$value": "#ADC3E1", "$type": "color" },
      "400": { "$value": "#84A5D1", "$type": "color" },
      "500": { "$value": "#5B87C2", "$type": "color" },
      "600": { "$value": "#4272B3", "$type": "color" },
      "700": { "$value": "#375F95", "$type": "color" },
      "800": { "$value": "#2C4C77", "$type": "color" },
      "900": { "$value": "#213959", "$type": "color" },
      "950": { "$value": "#162436", "$type": "color" }
    },
    "brandInk": { "$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 #213959 · 11.70:1
Use #ffffffAAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 11.70:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 1.79:1
AA fail · AA large fail · AAA fail
Reading the other direction: #213959 as text scores 11.70:1 on white and 1.79:1 on black.
Best tinted ink on it, if plain black or white feels flat: #ECF1F8 at 10.31:1.

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
#213959 · 11.70:1
AA on whitealready passes
#213959
The quick fox
#213959 · 11.70:1
AAA on whitealready passes
#213959
The quick fox
#4577BA · 4.60:1
AA on black+26% L
#4577BA
The quick fox
#759ACC · 7.25:1
AAA on black+39% L
#759ACC

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #213959 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
#213959 on white: 11.70:1
AA ✓ pass · AA-large · AAA
Aa
#213959 on black: 1.79:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #213959 as text on that neutral, and that neutral as text on #213959.

NeutralRatioBoth directions
White11.70:1AaAa
Slate 5011.19:1AaAa
Slate 10010.68:1AaAa
Slate 2009.49:1AaAa
Slate 3007.88:1AaAa
Slate 4004.56:1AaAa
Slate 5002.46:1AaAa
Slate 6001.54:1AaAa
Slate 7001.13:1AaAa
Slate 8001.25:1AaAa
Slate 9001.53:1AaAa
Black1.79:1AaAa
Colour vision deficiency
true color
protanopia · #2C3B5A
deuteranopia · #243658
tritanopia · #004045

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. #213959 is pinned to step 900; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F5F7FA
#EAEFF5
#D0DCEB
#ADC3E1
#84A5D1
#5B87C2
#4272B3
#375F95
#2C4C77
#213959
#162436
Base = 900Lightest = 50 · #F5F7FADarkest = 950 · #162436Text 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 0.016 256.1);
  --brand-100: oklch(0.94 0.026 256.1);
  --brand-200: oklch(0.88 0.038 256.1);
  --brand-300: oklch(0.80 0.050 256.1);
  --brand-400: oklch(0.72 0.059 256.1);
  --brand-500: oklch(0.64 0.064 256.1);
  --brand-600: oklch(0.56 0.064 256.1);
  --brand-700: oklch(0.48 0.060 256.1);
  --brand-800: oklch(0.40 0.054 256.1);
  --brand-900: oklch(0.32 0.045 256.1);
  --brand-950: oklch(0.24 0.035 256.1);
}

Colors that work with #213959

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#C3D4E9
Hairlines and dividers
Muted text#4B6D9B
Captions on the surface
Accent#5B321F
Second voice, not a rival
Dark variant#223C5D
Hover, pressed, headers
Light variant#ECF1F8
Selected rows, tints
Dark surface#141B24
Dark-mode background
Hover#17283F
One step down in lightness
Pressed#0E1825
Two steps down
Disabled#5B718F
Chroma pulled out
Focus ring#1F416F
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 #213959

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
  • Weight76/100
  • 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#594121
Analogous left#215559
Analogous right#252159
Split-complement 1#592521
Split-complement 2#555921
Triadic 1#592139
Triadic 2#395921
Tetradic#592155
On the wheel
Base+30°−30°+120°+240°+180°214°

#213959 sits at 214°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red12.9%
Green22.4%
Blue34.9%
R · 0–255
33
0x21
G · 0–255
57
0x39
B · 0–255
89
0x59

CMYK percentages

Cyan62.9%
Magenta36.0%
Yellow0.0%
Key (black)65.1%

Total ink coverage is 164%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#213959 text on a black background

contrast 1.79:1

Card sample

#213959 text on a white background

contrast 11.70:1

Card sample

#213959 on grey

10.68:1

#213959 on its own surface

10.89:1

#213959 on its dark surface

1.48:1

CSS3 live lab

Text font color

The quick brown fox

color: #213959;
Background color
Panel with #213959 background
background-color: #213959;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #213959;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(33, 57, 89, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(33, 57, 89, 0.45);
Border & gradient
Gradient panel
border: 3px solid #213959;
background: linear-gradient(135deg, #213959, #2E2159);
Gradient text

Gradient headline

background: linear-gradient(90deg, #213959, #3C2159);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #213959;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #213959;
caret-color: #213959;
Left rule
Pull quote or callout
border-left: 4px solid #213959;
Ring + tint
Selected chip
background: #ECF1F8;
box-shadow: inset 0 0 0 2px #213959;
Conic badge
68%
background: conic-gradient(#213959 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #213959 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(33, 57, 89, 0.5)
rgb(33 57 89 / 50%)
#21395980
hsl(214 46% 24% / 50%)
color-mix(in srgb, #213959 50%, transparent)
Alpha8-digit hexFlat on white
10%#2139591a#E9EBEE
20%#21395933#D3D7DE
40%#21395966#A6B0BD
60%#21395999#7A889B
80%#213959cc#4D617A

Gradients from #213959

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, #325686, #213959 45%, #223C5D);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #213959, #261943);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #213959, #594121);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #3A649C 0%, #213959 45%, #223C5D 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%, #2F7E7D 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #34296F 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #223C5D 0%, transparent 65%), #213959;

Monochromatic scale

Palettes built from #213959

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.

#213959 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

Very dark values collapse into each other on cheap panels — leave more lightness between your darkest steps than the numbers suggest.

In dark mode

Too dim on dark surfaces at 1.79:1 — lift it to #4577BA 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.

#213959, answered

What color is #213959?

#213959 is a deep vivid blue, closest to Dark Slate Blue (ΔE2000 11.2). It sits at 214° on the hue wheel with 46% saturation and 24% lightness, which reads as cool.

What is the RGB value of #213959?

rgb(33, 57, 89) — 33 red, 57 green and 89 blue out of 255, or 12.9% / 22.4% / 34.9% by channel.

What is #213959 in HSL and HSV?

hsl(214, 46%, 24%) and hsv(214, 63%, 35%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #213959 a light or a dark color?

It is a dark color. Relative luminance is 0.0397 and perceived brightness is 22%, so white text on it reaches 11.70:1.

Should I use black or white text on #213959?

White. It scores 11.70:1 against #213959, versus 1.79:1 for black — AAA at any size.

Is #213959 accessible on a white background?

#213959 on white scores 11.70:1, which clears AAA at every size.

What is the complementary color of #213959?

#594121 sits directly opposite on the wheel. Softer options are the split-complements #592521 and #555921, which give the same contrast with far less vibration.

What colors go well with #213959?

For interface work: #F4F7FA as the surface, #C3D4E9 for borders, #4B6D9B for secondary text, #5B321F as an accent and #223C5D for hover and pressed states. For a palette, the analogous pair #215559 and #252159 stays calm, while #594121 is the loudest partner.

What is #213959 in CMYK for printing?

cmyk(63%, 36%, 0%, 65%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #213959 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 #212459; nudged cooler, #192E47.

Which Tailwind color is closest to #213959?

The slate family — its 500 step is #64748b, ΔE2000 21 away. That is a visible difference, so define #213959 as a custom token rather than reaching for the built-in.

How do I use #213959 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#213959] or text-[#213959], 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 #213959 with 50% opacity?

rgba(33, 57, 89, 0.5), or #21395980 in eight-digit hex. Over white that composites to #909CAC; over black, #111D2D.

Is #213959 a web-safe color?

No. The nearest web-safe colour is #333366, ΔE2000 7.7 away. The palette only matters for legacy displays and some email clients now.

What does the color #213959 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 #213959?

The safest is same-hue elevation: linear-gradient(135deg, #325686, #213959 45%, #223C5D). For more colour, a short hue run to #261943 keeps it rich without turning muddy.

Work with #213959 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #213959 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.