#3f577b

At a glance

Every number on this page in one read: what #3f577b is made of, how bright it looks, and which way it leans.

Design tokens

The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.

:root {
  --brand-50: #F5F7F9;
  --brand-100: #ECEFF4;
  --brand-200: #D4DCE7;
  --brand-300: #B5C3D9;
  --brand-400: #90A5C6;
  --brand-500: #6B88B3;
  --brand-600: #5372A2;
  --brand-700: #3f577b;
  --brand-800: #374C6C;
  --brand-900: #2B3A4F;
  --brand-950: #1B2432;
  --brand: #3f577b;
  --brand-ink: #ffffff;
  --brand-surface: #F5F7FA;
  --brand-border: #C9D4E3;
  --brand-hover: #334664;
  --brand-pressed: #27364C;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #141A24;
    --brand-ink: #D7DEEA;
  }
}

theme: {
  extend: {
    colors: {
      brand: {
        50: '#F5F7F9',
        100: '#ECEFF4',
        200: '#D4DCE7',
        300: '#B5C3D9',
        400: '#90A5C6',
        500: '#6B88B3',
        600: '#5372A2',
        700: '#3f577b',
        800: '#374C6C',
        900: '#2B3A4F',
        950: '#1B2432',
        DEFAULT: '#3f577b',
      },
    },
  },
}

$brand: (
  '50': #F5F7F9,
  '100': #ECEFF4,
  '200': #D4DCE7,
  '300': #B5C3D9,
  '400': #90A5C6,
  '500': #6B88B3,
  '600': #5372A2,
  '700': #3f577b,
  '800': #374C6C,
  '900': #2B3A4F,
  '950': #1B2432,
);
$brand-base: #3f577b;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }

{
  "color": {
    "brand": {
      "50": { "$value": "#F5F7F9", "$type": "color" },
      "100": { "$value": "#ECEFF4", "$type": "color" },
      "200": { "$value": "#D4DCE7", "$type": "color" },
      "300": { "$value": "#B5C3D9", "$type": "color" },
      "400": { "$value": "#90A5C6", "$type": "color" },
      "500": { "$value": "#6B88B3", "$type": "color" },
      "600": { "$value": "#5372A2", "$type": "color" },
      "700": { "$value": "#3f577b", "$type": "color" },
      "800": { "$value": "#374C6C", "$type": "color" },
      "900": { "$value": "#2B3A4F", "$type": "color" },
      "950": { "$value": "#1B2432", "$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.

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.

Accessibility — WCAG contrast

Contrast is symmetric, so each row covers both directions: #3f577b as text on that neutral, and that neutral as text on #3f577b.

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. #3f577b 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.

:root {
  --brand-50: oklch(0.97 0.017 258.3);
  --brand-100: oklch(0.94 0.026 258.3);
  --brand-200: oklch(0.88 0.040 258.3);
  --brand-300: oklch(0.80 0.052 258.3);
  --brand-400: oklch(0.72 0.061 258.3);
  --brand-500: oklch(0.64 0.066 258.3);
  --brand-600: oklch(0.56 0.066 258.3);
  --brand-700: oklch(0.48 0.062 258.3);
  --brand-800: oklch(0.40 0.056 258.3);
  --brand-900: oklch(0.32 0.046 258.3);
  --brand-950: oklch(0.24 0.036 258.3);
}

Colors that work with #3f577b

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

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.

How to use #3f577b

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

Meaning and mood

What a colour in this family tends to signal, and how this particular chroma and lightness change the reading.

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.

Transparency

What each alpha value actually composites to. The top row is #3f577b over white; the bottom row is the same alpha over a checkerboard, so you can see what survives on a photo or a video.

rgba(63, 87, 123, 0.5)
rgb(63 87 123 / 50%)
#3f577b80
hsl(216 32% 37% / 50%)
color-mix(in srgb, #3f577b 50%, transparent)

Gradients from #3f577b

Six recipes, each built from this hex and shown with the exact CSS that produced it.

background: linear-gradient(135deg, #5474A4, #3f577b 45%, #2B3C54);

background: linear-gradient(120deg, #3f577b, #463567);

background: linear-gradient(90deg, #3f577b, #7B633F);

background: radial-gradient(120% 120% at 20% 0%, #6583B0 0%, #3f577b 45%, #2B3C54 100%);

background: linear-gradient(180deg, #F5F7FA, #ffffff);

background: radial-gradient(60% 60% at 15% 20%, #509C9D 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #56498F 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #2B3C54 0%, transparent 65%), #3f577b;

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.

#3f577b in the real world

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

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.