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blue · cool

#577c8f

a balanced, soft blue · cool · closest name: Slate Gray

Token name suggestion: Atlas Harbour

RGB
87, 124, 143
HSL
200°, 24%, 45%
CMYK
39, 13, 0, 44
Luminance
0.1842

#577c8f is a balanced soft blue, 200° on the wheel and 82/100 on the cool side. Put black text on it (4.68:1). As text it scores 4.48:1 on white — large text only. Nearest name is Slate Gray, nearest Tailwind family is slate.

hsl(200 24% 45%)rgb(87 124 143)Base step 600AA inkCool

At a glance

Every number on this page in one read: what #577c8f is made of, how bright it looks, and which way it leans.

Hex
#577c8f
Hue
200°
blue
Saturation
24%
soft
Lightness
45%
balanced
Brightness
56%
HSV value
Perceived
46%
weighted brightness
Luminance
0.1842
WCAG relative
Temperature
Cool
82/100 cool
Color family
Blue
Tone
Soft
Best ink
Black
4.68:1
Closest name
Slate Gray
ΔE2000 6.7
Chroma
16.4
LCH, 0–130ish
OKLCH L
0.566
perceptual lightness
Tailwind
slate
500 · ΔE 8.1
Web-safe
#666699
nearest of 216
Where it sits
Hue200° of 360°
Saturation24%
Lightness45%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #577c8f.

Temperature
Warm ← → Cool82% 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
Red11%
Green78%
Blue11%

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

Every format

HEX#577c8f
HEX (8-digit)#577c8fff
RGBrgb(87, 124, 143)
RGBArgba(87, 124, 143, 1)
HSLhsl(200, 24%, 45%)
HSV / HSBhsv(200, 39%, 56%)
HWBhwb(200 34% 44%)
CMYKcmyk(39%, 13%, 0%, 44%)
LABlab(50.0 -7.9 -14.4)
LCHlch(50.0 16.4 241.3)
OKLCHoklch(0.566 0.051 231.1)
XYZ (D65)xyz(16.09, 18.42, 28.69)
Decimal5733519
Display P3color(display-p3 0.341 0.486 0.561)
Web-safe#666699

Copy-ready code

every platformclick to select
/* CSS */
color: #577c8f;
background-color: #577c8f;
/* CSS custom property */
--brand: #577c8f;
/* Tailwind (arbitrary) */
class="text-[#577c8f] bg-[#577c8f]"
/* SCSS */
$brand: #577c8f;
/* SwiftUI */
Color(red: 0.341, green: 0.486, blue: 0.561)
/* UIKit */
UIColor(red: 0.341, green: 0.486, blue: 0.561, alpha: 1)
/* Android XML */
<color name="brand">#577C8F</color>
/* Android Compose */
Color(0xFF577C8F)
/* Flutter */
Color(0xFF577C8F)
/* Python / OpenCV (BGR) */
(143, 124, 87)
/* Python / PIL (RGB) */
(87, 124, 143)
/* Java AWT */
new Color(87, 124, 143)
/* .NET */
Color.FromArgb(255, 87, 124, 143)
/* OpenGL / Unity (0–1) */
(0.3412f, 0.4863f, 0.5608f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{87,124,143}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #577c8f 85%, white);
border-color: color-mix(in oklab, #577c8f 40%, transparent);
/* theme-aware in one line */
color: light-dark(#30454F, #D9E3E8);
/* relative colour syntax */
--hover: hsl(from #577c8f 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: #F6F8F9;
  --brand-100: #EDF1F3;
  --brand-200: #D7E0E5;
  --brand-300: #B9CBD5;
  --brand-400: #96B1BF;
  --brand-500: #7498AA;
  --brand-600: #577c8f;
  --brand-700: #4D6E7F;
  --brand-800: #3E5865;
  --brand-900: #30424B;
  --brand-950: #1E292F;
  --brand: #577c8f;
  --brand-ink: #000000;
  --brand-surface: #F5F8F9;
  --brand-border: #CCD9E0;
  --brand-hover: #4A6979;
  --brand-pressed: #3C5563;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #151E23;
    --brand-ink: #D9E3E8;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F6F8F9',
        100: '#EDF1F3',
        200: '#D7E0E5',
        300: '#B9CBD5',
        400: '#96B1BF',
        500: '#7498AA',
        600: '#577c8f',
        700: '#4D6E7F',
        800: '#3E5865',
        900: '#30424B',
        950: '#1E292F',
        DEFAULT: '#577c8f',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F6F8F9,
  '100': #EDF1F3,
  '200': #D7E0E5,
  '300': #B9CBD5,
  '400': #96B1BF,
  '500': #7498AA,
  '600': #577c8f,
  '700': #4D6E7F,
  '800': #3E5865,
  '900': #30424B,
  '950': #1E292F,
);
$brand-base: #577c8f;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F6F8F9", "$type": "color" },
      "100": { "$value": "#EDF1F3", "$type": "color" },
      "200": { "$value": "#D7E0E5", "$type": "color" },
      "300": { "$value": "#B9CBD5", "$type": "color" },
      "400": { "$value": "#96B1BF", "$type": "color" },
      "500": { "$value": "#7498AA", "$type": "color" },
      "600": { "$value": "#577c8f", "$type": "color" },
      "700": { "$value": "#4D6E7F", "$type": "color" },
      "800": { "$value": "#3E5865", "$type": "color" },
      "900": { "$value": "#30424B", "$type": "color" },
      "950": { "$value": "#1E292F", "$type": "color" }
    },
    "brandInk": { "$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 #577c8f · 4.68:1
Use #000000AA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 4.48:1
AA fail · AA large pass · AAA fail
Aa
Black text · 4.68:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #577c8f as text scores 4.48:1 on white and 4.68:1 on black.
Best tinted ink on it, if plain black or white feels flat: #30454F at 2.24:1.

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
#55798C · 4.67:1
AA on white−1% L
#55798C
The quick fox
#405B69 · 7.20:1
AAA on white−12% L
#405B69
The quick fox
#577c8f · 4.68:1
AA on blackalready passes
#577c8f
The quick fox
#779AAC · 7.00:1
AAA on black+12% L
#779AAC

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #577C8F 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
#577c8f on white: 4.48:1
AA ✗ fail · AA-large · AAA
Aa
#577c8f on black: 4.68:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #577c8f as text on that neutral, and that neutral as text on #577c8f.

NeutralRatioBoth directions
White4.48:1AaAa
Slate 504.28:1AaAa
Slate 1004.09:1AaAa
Slate 2003.64:1AaAa
Slate 3003.02:1AaAa
Slate 4001.75:1AaAa
Slate 5001.06:1AaAa
Slate 6001.69:1AaAa
Slate 7002.31:1AaAa
Slate 8003.26:1AaAa
Slate 9003.98:1AaAa
Black4.68:1AaAa
Colour vision deficiency
true color
protanopia · #737B90
deuteranopia · #6B748F
tritanopia · #428182

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. #577c8f 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.

#F6F8F9
#EDF1F3
#D7E0E5
#B9CBD5
#96B1BF
#7498AA
#577c8f
#4D6E7F
#3E5865
#30424B
#1E292F
Base = 600Lightest = 50 · #F6F8F9Darkest = 950 · #1E292FText 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 0.013 231.1);
  --brand-100: oklch(0.94 0.020 231.1);
  --brand-200: oklch(0.88 0.031 231.1);
  --brand-300: oklch(0.80 0.040 231.1);
  --brand-400: oklch(0.72 0.047 231.1);
  --brand-500: oklch(0.64 0.051 231.1);
  --brand-600: oklch(0.56 0.051 231.1);
  --brand-700: oklch(0.48 0.048 231.1);
  --brand-800: oklch(0.40 0.043 231.1);
  --brand-900: oklch(0.32 0.036 231.1);
  --brand-950: oklch(0.24 0.028 231.1);
}

Colors that work with #577c8f

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#F5F8F9
Tinted page background
Border#CCD9E0
Hairlines and dividers
Muted text#577C8F
Captions on the surface
Accent#945852
Second voice, not a rival
Dark variant#30454F
Hover, pressed, headers
Light variant#EFF3F5
Selected rows, tints
Dark surface#151E23
Dark-mode background
Hover#4A6979
One step down in lightness
Pressed#3C5563
Two steps down
Disabled#99B1BE
Chroma pulled out
Focus ring#528BA8
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 #577c8f

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 #30454F
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
  • Weight55/100
  • 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#8F6A57
Analogous left#578F86
Analogous right#57608F
Split-complement 1#8F5760
Split-complement 2#8F8657
Triadic 1#8F577C
Triadic 2#7C8F57
Tetradic#86578F
On the wheel
Base+30°−30°+120°+240°+180°200°

#577c8f sits at 200°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red34.1%
Green48.6%
Blue56.1%
R · 0–255
87
0x57
G · 0–255
124
0x7c
B · 0–255
143
0x8f

CMYK percentages

Cyan39.2%
Magenta13.3%
Yellow0.0%
Key (black)43.9%

Total ink coverage is 96%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#577c8f text on a black background

contrast 4.68:1

Card sample

#577c8f text on a white background

contrast 4.48:1

Card sample

#577c8f on grey

4.09:1

#577c8f on its own surface

4.20:1

#577c8f on its dark surface

3.77:1

CSS3 live lab

Text font color

The quick brown fox

color: #577c8f;
Background color
Panel with #577c8f background
background-color: #577c8f;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #577c8f;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(87, 124, 143, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(87, 124, 143, 0.45);
Border & gradient
Gradient panel
border: 3px solid #577c8f;
background: linear-gradient(135deg, #577c8f, #57578F);
Gradient text

Gradient headline

background: linear-gradient(90deg, #577c8f, #65578F);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #577c8f;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #577c8f;
caret-color: #577c8f;
Left rule
Pull quote or callout
border-left: 4px solid #577c8f;
Ring + tint
Selected chip
background: #EFF3F5;
box-shadow: inset 0 0 0 2px #577c8f;
Conic badge
68%
background: conic-gradient(#577c8f 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #577c8f 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(87, 124, 143, 0.5)
rgb(87 124 143 / 50%)
#577c8f80
hsl(200 24% 45% / 50%)
color-mix(in srgb, #577c8f 50%, transparent)
Alpha8-digit hexFlat on white
10%#577c8f1a#EEF2F4
20%#577c8f33#DDE5E9
40%#577c8f66#BCCBD2
60%#577c8f99#9AB0BC
80%#577c8fcc#7996A5

Gradients from #577c8f

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, #779AAC, #577c8f 45%, #30454F);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #577c8f, #504B7C);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #577c8f, #8F6A57);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #8AA8B8 0%, #577c8f 45%, #30454F 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F5F8F9, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #71A89B 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #6469A1 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #30454F 0%, transparent 65%), #577c8f;

Monochromatic scale

Palettes built from #577c8f

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.

#577c8f 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 4.68:1.

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.

#577c8f, answered

What color is #577c8f?

#577c8f is a balanced soft blue, closest to Slate Gray (ΔE2000 6.7). It sits at 200° on the hue wheel with 24% saturation and 45% lightness, which reads as cool.

What is the RGB value of #577c8f?

rgb(87, 124, 143) — 87 red, 124 green and 143 blue out of 255, or 34.1% / 48.6% / 56.1% by channel.

What is #577c8f in HSL and HSV?

hsl(200, 24%, 45%) and hsv(200, 39%, 56%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #577c8f a light or a dark color?

It is a mid-tone. Relative luminance is 0.1842 and perceived brightness is 46%, so black text on it reaches 4.68:1.

Should I use black or white text on #577c8f?

Black. It scores 4.68:1 against #577c8f, versus 4.48:1 for white — AA at any size.

Is #577c8f accessible on a white background?

#577c8f on white scores 4.48:1, which only clears AA for large text — 18.66px bold or 24px regular and up. Darken it to #55798C to reach 4.5:1, or #405B69 for 7:1.

What is the complementary color of #577c8f?

#8F6A57 sits directly opposite on the wheel. Softer options are the split-complements #8F5760 and #8F8657, which give the same contrast with far less vibration.

What colors go well with #577c8f?

For interface work: #F5F8F9 as the surface, #CCD9E0 for borders, #577C8F for secondary text, #945852 as an accent and #30454F for hover and pressed states. For a palette, the analogous pair #578F86 and #57608F stays calm, while #8F6A57 is the loudest partner.

What is #577c8f in CMYK for printing?

cmyk(39%, 13%, 0%, 44%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #577c8f warm or cool?

Cool — it scores 82 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #578F8D; nudged cooler, #557491.

Which Tailwind color is closest to #577c8f?

The slate family — its 500 step is #64748b, ΔE2000 8.1 away. That is a visible difference, so define #577c8f as a custom token rather than reaching for the built-in.

How do I use #577c8f in Tailwind CSS?

Inline it as an arbitrary value with bg-[#577c8f] or text-[#577c8f], 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 #577c8f with 50% opacity?

rgba(87, 124, 143, 0.5), or #577c8f80 in eight-digit hex. Over white that composites to #ABBEC7; over black, #2C3E48.

Is #577c8f a web-safe color?

No. The nearest web-safe colour is #666699, ΔE2000 16.4 away. The palette only matters for legacy displays and some email clients now.

What does the color #577c8f 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 #577c8f?

The safest is same-hue elevation: linear-gradient(135deg, #779AAC, #577c8f 45%, #30454F). For more colour, a short hue run to #504B7C keeps it rich without turning muddy.

Work with #577c8f in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #577c8f at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.