#3D399F is a mid-toned, cool violet. On the Color Lab it reads clean and engineered, quietly premium. It carries a legible label as a UI accent and sits well as a supporting tone.
Not just a swatch — here's how #3D399F works with other colors. Named schemes with #3D399F in its natural role, and a note on why the supporting colors balance it.
Dark Slate Blue opens this coastal palette with sea-glass and warm sand alongside it, grounded by driftwood grey and a deep-navy anchor.
Dark Slate Blue 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 Blue anchors this café scheme as the warm mid-tone, lifted by latte cream and a muted sage accent and grounded by espresso brown and a warm charcoal.
Dark Slate Blue sits between cream and a deep berry here, softened by a blush accent and grounded by charcoal.
Dark Slate Blue 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 Blue carrying the quiet middle.
How #3D399F 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 #3D399F at work across the surfaces designers actually ship.
:root {
--color-base: #3D399F;
--color-base-rgb: 61 57 159;
--color-base-oklch: oklch(41.4% 0.160 278.5);
--color-50: #F4F3FB;
--color-100: #E1E0F5;
--color-200: #C4C3E9;
--color-300: #9B99D6;
--color-400: #7572C0;
--color-500: #5451A4;
--color-600: #46447E;
--color-700: #36345A;
--color-800: #26253C;
--color-900: #191825;
--color-on-base: #FFFFFF;
}
// tailwind.config.js
colors: {
dark-slate-blue: {
50: '#F4F3FB',
100: '#E1E0F5',
200: '#C4C3E9',
300: '#9B99D6',
400: '#7572C0',
500: '#5451A4',
600: '#46447E',
700: '#36345A',
800: '#26253C',
900: '#191825',
},
}
$base: #3D399F; $base-ink: #FFFFFF; $base-50: #F4F3FB; $base-100: #E1E0F5; $base-200: #C4C3E9; $base-300: #9B99D6; $base-400: #7572C0; $base-500: #5451A4; $base-600: #46447E; $base-700: #36345A; $base-800: #26253C; $base-900: #191825; $base-hover: #302D7E; $base-subtle: #C4C3E2;
{
"color": {
"base": {
"value": "#3D399F",
"type": "color"
},
"onBase": {
"value": "#FFFFFF",
"type": "color"
},
"scale": {
"50": {
"value": "#F4F3FB",
"type": "color"
},
"100": {
"value": "#E1E0F5",
"type": "color"
},
"200": {
"value": "#C4C3E9",
"type": "color"
},
"300": {
"value": "#9B99D6",
"type": "color"
},
"400": {
"value": "#7572C0",
"type": "color"
},
"500": {
"value": "#5451A4",
"type": "color"
},
"600": {
"value": "#46447E",
"type": "color"
},
"700": {
"value": "#36345A",
"type": "color"
},
"800": {
"value": "#26253C",
"type": "color"
},
"900": {
"value": "#191825",
"type": "color"
}
}
}
}