Cobalt Night

CSS

:root {
  --cobalt-night: #353739;
  --cobalt-night-rgb: 53 55 57;
  --cobalt-night-oklch: oklch(0.336 0.004 248);
}

.element {
  color: var(--cobalt-night);
  background-color: hsl(210 4% 22%);
  border-color: oklch(0.336 0.004 248);
}

Tailwind CSS v4

@theme {
  --color-cobalt-night: #353739;
  --color-cobalt-night-50: #f4f5f6;
  --color-cobalt-night-100: #e7e8e9;
  --color-cobalt-night-200: #d3d4d6;
  --color-cobalt-night-300: #b6b7b9;
  --color-cobalt-night-400: #9c9fa1;
  --color-cobalt-night-500: #848689;
  --color-cobalt-night-600: #707274;
  --color-cobalt-night-700: #595b5d;
  --color-cobalt-night-800: #414244;
  --color-cobalt-night-900: #2d2e2f;
  --color-cobalt-night-950: #1a1b1b;
}

SCSS

$cobalt-night: #353739;
$cobalt-night-rgb: 53, 55, 57;
$cobalt-night-light: mix(#fff, $cobalt-night, 20%);
$cobalt-night-dark: mix(#000, $cobalt-night, 20%);

.element {
  color: $cobalt-night;
  box-shadow: 0 0 0 2px rgba($cobalt-night, 0.35);
}