#255669 is a mid-toned, cool blue. On the Color Lab it reads clean and engineered, quietly premium. It carries a legible label as a UI accent and reproduces cleanly in print.
Not just a swatch — here's how #255669 works with other colors. Named schemes with #255669 in its natural role, and a note on why the supporting colors balance it.
Dark Slate Gray opens this coastal palette with sea-glass and warm sand alongside it, grounded by driftwood grey and a deep-navy anchor.
Dark Slate Gray keeps this Nordic scheme quiet — cool greys and a soft white around it, a muted-blue support and a charcoal anchor.
Dark Slate Gray is the vivid signal in this product UI — on a near-black surface with cool white, a slate grey and a lighter tint of Dark Slate Gray.
Dark Slate Gray plays the worn-leather lead, deepened by saddle brown and an oxblood anchor, softened by aged cream and cooled by a muted forest green.
Dark Slate Gray is the single accent in this high-contrast editorial system — set on near-white paper against near-black ink, with a warm grey and a desaturated tint of Dark Slate Gray carrying the quiet middle.
How #255669 actually behaves in design work — read from its OKLCH lightness, chroma and hue, not just its raw numbers. Ten signals to help you decide where this color earns its place.
Not a swatch to memorise — a color to build with. Here is #255669 at work across the surfaces designers actually ship.
:root {
--color-base: #255669;
--color-base-rgb: 37 86 105;
--color-base-oklch: oklch(42.8% 0.061 226.4);
--color-50: #F3F9FB;
--color-100: #E0EFF5;
--color-200: #C3DFEA;
--color-300: #99C5D7;
--color-400: #71AAC1;
--color-500: #508DA5;
--color-600: #436E7F;
--color-700: #34505B;
--color-800: #25353C;
--color-900: #182125;
--color-on-base: #FFFFFF;
}
// tailwind.config.js
colors: {
dark-slate-gray: {
50: '#F3F9FB',
100: '#E0EFF5',
200: '#C3DFEA',
300: '#99C5D7',
400: '#71AAC1',
500: '#508DA5',
600: '#436E7F',
700: '#34505B',
800: '#25353C',
900: '#182125',
},
}
$base: #255669; $base-ink: #FFFFFF; $base-50: #F3F9FB; $base-100: #E0EFF5; $base-200: #C3DFEA; $base-300: #99C5D7; $base-400: #71AAC1; $base-500: #508DA5; $base-600: #436E7F; $base-700: #34505B; $base-800: #25353C; $base-900: #182125; $base-hover: #1E4555; $base-subtle: #B4D1DC;
{
"color": {
"base": {
"value": "#255669",
"type": "color"
},
"onBase": {
"value": "#FFFFFF",
"type": "color"
},
"scale": {
"50": {
"value": "#F3F9FB",
"type": "color"
},
"100": {
"value": "#E0EFF5",
"type": "color"
},
"200": {
"value": "#C3DFEA",
"type": "color"
},
"300": {
"value": "#99C5D7",
"type": "color"
},
"400": {
"value": "#71AAC1",
"type": "color"
},
"500": {
"value": "#508DA5",
"type": "color"
},
"600": {
"value": "#436E7F",
"type": "color"
},
"700": {
"value": "#34505B",
"type": "color"
},
"800": {
"value": "#25353C",
"type": "color"
},
"900": {
"value": "#182125",
"type": "color"
}
}
}
}