#357294

CSS

:root {
  --harbour-blue: #357294;
  --harbour-blue-rgb: 53 114 148;
  --harbour-blue-oklch: oklch(0.527 0.083 235.7);
}

.element {
  color: var(--harbour-blue);
  background-color: hsl(201 47% 39%);
  border-color: oklch(0.527 0.083 235.7);
}

Tailwind CSS v4

@theme {
  --color-harbour-blue: #357294;
  --color-harbour-blue-50: #e0f9ff;
  --color-harbour-blue-100: #cfedff;
  --color-harbour-blue-200: #b4daf4;
  --color-harbour-blue-300: #90bedd;
  --color-harbour-blue-400: #6da6c9;
  --color-harbour-blue-500: #4a8fb5;
  --color-harbour-blue-600: #407999;
  --color-harbour-blue-700: #33617b;
  --color-harbour-blue-800: #22475b;
  --color-harbour-blue-900: #17313f;
  --color-harbour-blue-950: #071d28;
}

SCSS

$harbour-blue: #357294;
$harbour-blue-rgb: 53, 114, 148;
$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);
}