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cyan · cool

#257591

a dark, vivid cyan · cool · closest name: Steel Blue

Token name suggestion: Shadow Glacier

RGB
37, 117, 145
HSL
196°, 59%, 36%
CMYK
75, 19, 0, 43
Luminance
0.1516

#257591 is a dark vivid cyan, 196° on the wheel and 94/100 on the cool side. Put white text on it (5.21:1). As text it scores 5.21:1 on white — safe at any size. Nearest name is Steel Blue, nearest Tailwind family is slate.

hsl(196 59% 36%)rgb(37 117 145)Base step 800AA inkCool

At a glance

Every number on this page in one read: what #257591 is made of, how bright it looks, and which way it leans.

Hex
#257591
Hue
196°
cyan
Saturation
59%
vivid
Lightness
36%
dark
Brightness
57%
HSV value
Perceived
41%
weighted brightness
Luminance
0.1516
WCAG relative
Temperature
Cool
94/100 cool
Color family
Cyan
Tone
Vivid
Best ink
White
5.21:1
Closest name
Steel Blue
ΔE2000 10.4
Chroma
26.3
LCH, 0–130ish
OKLCH L
0.527
perceptual lightness
Tailwind
slate
500 · ΔE 12.8
Web-safe
#336699
nearest of 216
Where it sits
Hue196° of 360°
Saturation59%
Lightness36%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #257591.

Temperature
Warm ← → Cool94% 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
Red3%
Green84%
Blue13%

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

Every format

HEX#257591
HEX (8-digit)#257591ff
RGBrgb(37, 117, 145)
RGBArgba(37, 117, 145, 1)
HSLhsl(196, 59%, 36%)
HSV / HSBhsv(196, 74%, 57%)
HWBhwb(196 15% 43%)
CMYKcmyk(75%, 19%, 0%, 43%)
LABlab(45.9 -14.2 -22.1)
LCHlch(45.9 26.3 237.4)
OKLCHoklch(0.527 0.087 225.7)
XYZ (D65)xyz(12.23, 15.16, 29.06)
Decimal2454929
Display P3color(display-p3 0.145 0.459 0.569)
Web-safe#336699

Copy-ready code

every platformclick to select
/* CSS */
color: #257591;
background-color: #257591;
/* CSS custom property */
--brand: #257591;
/* Tailwind (arbitrary) */
class="text-[#257591] bg-[#257591]"
/* SCSS */
$brand: #257591;
/* SwiftUI */
Color(red: 0.145, green: 0.459, blue: 0.569)
/* UIKit */
UIColor(red: 0.145, green: 0.459, blue: 0.569, alpha: 1)
/* Android XML */
<color name="brand">#257591</color>
/* Android Compose */
Color(0xFF257591)
/* Flutter */
Color(0xFF257591)
/* Python / OpenCV (BGR) */
(145, 117, 37)
/* Python / PIL (RGB) */
(37, 117, 145)
/* Java AWT */
new Color(37, 117, 145)
/* .NET */
Color.FromArgb(255, 37, 117, 145)
/* OpenGL / Unity (0–1) */
(0.1451f, 0.4588f, 0.5686f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{37,117,145}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #257591 85%, white);
border-color: color-mix(in oklab, #257591 40%, transparent);
/* theme-aware in one line */
color: light-dark(#1A5266, #D3E7EE);
/* relative colour syntax */
--hover: hsl(from #257591 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: #F4F9FB;
  --brand-100: #E9F3F7;
  --brand-200: #CDE6EF;
  --brand-300: #A6D7E8;
  --brand-400: #79C3DD;
  --brand-500: #4CAFD1;
  --brand-600: #329DC3;
  --brand-700: #2A83A2;
  --brand-800: #257591;
  --brand-900: #1C4D5F;
  --brand-950: #11303B;
  --brand: #257591;
  --brand-ink: #ffffff;
  --brand-surface: #F4F9FA;
  --brand-border: #C0E1ED;
  --brand-hover: #1E5E75;
  --brand-pressed: #174758;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142024;
    --brand-ink: #D3E7EE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F4F9FB',
        100: '#E9F3F7',
        200: '#CDE6EF',
        300: '#A6D7E8',
        400: '#79C3DD',
        500: '#4CAFD1',
        600: '#329DC3',
        700: '#2A83A2',
        800: '#257591',
        900: '#1C4D5F',
        950: '#11303B',
        DEFAULT: '#257591',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F4F9FB,
  '100': #E9F3F7,
  '200': #CDE6EF,
  '300': #A6D7E8,
  '400': #79C3DD,
  '500': #4CAFD1,
  '600': #329DC3,
  '700': #2A83A2,
  '800': #257591,
  '900': #1C4D5F,
  '950': #11303B,
);
$brand-base: #257591;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F4F9FB", "$type": "color" },
      "100": { "$value": "#E9F3F7", "$type": "color" },
      "200": { "$value": "#CDE6EF", "$type": "color" },
      "300": { "$value": "#A6D7E8", "$type": "color" },
      "400": { "$value": "#79C3DD", "$type": "color" },
      "500": { "$value": "#4CAFD1", "$type": "color" },
      "600": { "$value": "#329DC3", "$type": "color" },
      "700": { "$value": "#2A83A2", "$type": "color" },
      "800": { "$value": "#257591", "$type": "color" },
      "900": { "$value": "#1C4D5F", "$type": "color" },
      "950": { "$value": "#11303B", "$type": "color" }
    },
    "brandInk": { "$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 #257591 · 5.21:1
Use #ffffffAA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 5.21:1 · recommended
AA pass · AA large pass · AAA fail
Aa
Black text · 4.03:1
AA fail · AA large pass · AAA fail
Reading the other direction: #257591 as text scores 5.21:1 on white and 4.03:1 on black.
Best tinted ink on it, if plain black or white feels flat: #EBF6FA at 4.74:1.

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
#257591 · 5.21:1
AA on whitealready passes
#257591
The quick fox
#1E5E75 · 7.21:1
AAA on white−7% L
#1E5E75
The quick fox
#287F9D · 4.61:1
AA on black+3% L
#287F9D
The quick fox
#34A3CA · 7.24:1
AAA on black+14% L
#34A3CA

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #257591 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
#257591 on white: 5.21:1
AA ✓ pass · AA-large · AAA
Aa
#257591 on black: 4.03:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #257591 as text on that neutral, and that neutral as text on #257591.

NeutralRatioBoth directions
White5.21:1AaAa
Slate 504.98:1AaAa
Slate 1004.75:1AaAa
Slate 2004.22:1AaAa
Slate 3003.51:1AaAa
Slate 4002.03:1AaAa
Slate 5001.09:1AaAa
Slate 6001.45:1AaAa
Slate 7001.99:1AaAa
Slate 8002.81:1AaAa
Slate 9003.43:1AaAa
Black4.03:1AaAa
Colour vision deficiency
true color
protanopia · #667392
deuteranopia · #576891
tritanopia · #007D7E

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. #257591 is pinned to step 800; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F4F9FB
#E9F3F7
#CDE6EF
#A6D7E8
#79C3DD
#4CAFD1
#329DC3
#2A83A2
#257591
#1C4D5F
#11303B
Base = 800Lightest = 50 · #F4F9FBDarkest = 950 · #11303BText step on white = 800
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 0.022 225.7);
  --brand-100: oklch(0.94 0.035 225.7);
  --brand-200: oklch(0.88 0.052 225.7);
  --brand-300: oklch(0.80 0.068 225.7);
  --brand-400: oklch(0.72 0.080 225.7);
  --brand-500: oklch(0.64 0.087 225.7);
  --brand-600: oklch(0.56 0.087 225.7);
  --brand-700: oklch(0.48 0.081 225.7);
  --brand-800: oklch(0.40 0.073 225.7);
  --brand-900: oklch(0.32 0.061 225.7);
  --brand-950: oklch(0.24 0.048 225.7);
}

Colors that work with #257591

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#F4F9FA
Tinted page background
Border#C0E1ED
Hairlines and dividers
Muted text#4B869B
Captions on the surface
Accent#952321
Second voice, not a rival
Dark variant#1A5266
Hover, pressed, headers
Light variant#EBF6FA
Selected rows, tints
Dark surface#142024
Dark-mode background
Hover#1E5E75
One step down in lightness
Pressed#174758
Two steps down
Disabled#7B9FAB
Chroma pulled out
Focus ring#1F87AB
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 #257591

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
  • Full-page backgrounds — tiring over long sessions
  • Black text placed on it
  • Thin strokes and 1px borders — they disappear on light UI
  • 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.

cleantechnicalfreshclinical

Cyan reads as water, air and infrastructure: cool, hygienic, engineered.

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

At high lightness it disappears into white surfaces and thin strokes vanish entirely.

Reads as
  • FormalityHigh
  • EnergyMedium-high
  • Weight64/100
  • 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#914125
Analogous left#259177
Analogous right#253F91
Split-complement 1#91253F
Split-complement 2#917725
Triadic 1#912575
Triadic 2#759125
Tetradic#772591
On the wheel
Base+30°−30°+120°+240°+180°196°

#257591 sits at 196°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red14.5%
Green45.9%
Blue56.9%
R · 0–255
37
0x25
G · 0–255
117
0x75
B · 0–255
145
0x91

CMYK percentages

Cyan74.5%
Magenta19.3%
Yellow0.0%
Key (black)43.1%

Total ink coverage is 137%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#257591 text on a black background

contrast 4.03:1

Card sample

#257591 text on a white background

contrast 5.21:1

Card sample

#257591 on grey

4.75:1

#257591 on its own surface

4.91:1

#257591 on its dark surface

3.20:1

CSS3 live lab

Text font color

The quick brown fox

color: #257591;
Background color
Panel with #257591 background
background-color: #257591;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #257591;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(37, 117, 145, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(37, 117, 145, 0.45);
Border & gradient
Gradient panel
border: 3px solid #257591;
background: linear-gradient(135deg, #257591, #252D91);
Gradient text

Gradient headline

background: linear-gradient(90deg, #257591, #382591);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #257591;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #257591;
caret-color: #257591;
Left rule
Pull quote or callout
border-left: 4px solid #257591;
Ring + tint
Selected chip
background: #EBF6FA;
box-shadow: inset 0 0 0 2px #257591;
Conic badge
68%
background: conic-gradient(#257591 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #257591 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(37, 117, 145, 0.5)
rgb(37 117 145 / 50%)
#25759180
hsl(196 59% 36% / 50%)
color-mix(in srgb, #257591 50%, transparent)
Alpha8-digit hexFlat on white
10%#2575911a#E9F1F4
20%#25759133#D3E3E9
40%#25759166#A8C8D3
60%#25759199#7CACBD
80%#257591cc#5191A7

Gradients from #257591

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, #329CC2, #257591 45%, #1A5266);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #257591, #201F79);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #257591, #914125);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #43ABCF 0%, #257591 45%, #1A5266 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4F9FA, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #2FBA8D 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #2B3FA9 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #1A5266 0%, transparent 65%), #257591;

Monochromatic scale

Palettes built from #257591

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.

#257591 in the real world

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

Industries
TechnologyTravelHealthcareMedia
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 4.03:1 — lift it to #287F9D 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.

#257591, answered

What color is #257591?

#257591 is a dark vivid cyan, closest to Steel Blue (ΔE2000 10.4). It sits at 196° on the hue wheel with 59% saturation and 36% lightness, which reads as cool.

What is the RGB value of #257591?

rgb(37, 117, 145) — 37 red, 117 green and 145 blue out of 255, or 14.5% / 45.9% / 56.9% by channel.

What is #257591 in HSL and HSV?

hsl(196, 59%, 36%) and hsv(196, 74%, 57%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #257591 a light or a dark color?

It is a dark color. Relative luminance is 0.1516 and perceived brightness is 41%, so white text on it reaches 5.21:1.

Should I use black or white text on #257591?

White. It scores 5.21:1 against #257591, versus 4.03:1 for black — AA at any size.

Is #257591 accessible on a white background?

#257591 on white scores 5.21:1, which clears AA at every size but not AAA.

What is the complementary color of #257591?

#914125 sits directly opposite on the wheel. Softer options are the split-complements #91253F and #917725, which give the same contrast with far less vibration.

What colors go well with #257591?

For interface work: #F4F9FA as the surface, #C0E1ED for borders, #4B869B for secondary text, #952321 as an accent and #1A5266 for hover and pressed states. For a palette, the analogous pair #259177 and #253F91 stays calm, while #914125 is the loudest partner.

What is #257591 in CMYK for printing?

cmyk(75%, 19%, 0%, 43%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #257591 warm or cool?

Cool — it scores 94 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #259186; nudged cooler, #236393.

Which Tailwind color is closest to #257591?

The slate family — its 500 step is #64748b, ΔE2000 12.8 away. That is a visible difference, so define #257591 as a custom token rather than reaching for the built-in.

How do I use #257591 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#257591] or text-[#257591], 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 #257591 with 50% opacity?

rgba(37, 117, 145, 0.5), or #25759180 in eight-digit hex. Over white that composites to #92BAC8; over black, #133B49.

Is #257591 a web-safe color?

No. The nearest web-safe colour is #336699, ΔE2000 10.8 away. The palette only matters for legacy displays and some email clients now.

What does the color #257591 mean?

As a cyan, it reads clean, technical, fresh. Cyan reads as water, air and infrastructure: cool, hygienic, engineered. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #257591?

The safest is same-hue elevation: linear-gradient(135deg, #329CC2, #257591 45%, #1A5266). For more colour, a short hue run to #201F79 keeps it rich without turning muddy.

Work with #257591 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #257591 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.