#447190

CSS

:root {
  --harbour-blue: #447190;
  --harbour-blue-rgb: 68 113 144;
  --harbour-blue-oklch: oklch(0.529 0.07 240);
}

.element {
  color: var(--harbour-blue);
  background-color: hsl(204 36% 42%);
  border-color: oklch(0.529 0.07 240);
}

Tailwind CSS v4

@theme {
  --color-harbour-blue: #447190;
  --color-harbour-blue-50: #e5f8ff;
  --color-harbour-blue-100: #d4ebfe;
  --color-harbour-blue-200: #bbd9f0;
  --color-harbour-blue-300: #99bcd9;
  --color-harbour-blue-400: #79a4c4;
  --color-harbour-blue-500: #5a8db0;
  --color-harbour-blue-600: #4c7795;
  --color-harbour-blue-700: #3d5f77;
  --color-harbour-blue-800: #2a4658;
  --color-harbour-blue-900: #1c303d;
  --color-harbour-blue-950: #0c1d27;
}

SCSS

$harbour-blue: #447190;
$harbour-blue-rgb: 68, 113, 144;
$harbour-blue-light: mix(#fff, $harbour-blue, 20%);
$harbour-blue-dark: mix(#000, $harbour-blue, 20%);

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