#327393

CSS

:root {
  --harbour-blue: #327393;
  --harbour-blue-rgb: 50 115 147;
  --harbour-blue-oklch: oklch(0.527 0.083 232.8);
}

.element {
  color: var(--harbour-blue);
  background-color: hsl(200 49% 39%);
  border-color: oklch(0.527 0.083 232.8);
}

Tailwind CSS v4

@theme {
  --color-harbour-blue: #327393;
  --color-harbour-blue-50: #dffaff;
  --color-harbour-blue-100: #ceedff;
  --color-harbour-blue-200: #b3dbf3;
  --color-harbour-blue-300: #8ebfdc;
  --color-harbour-blue-400: #6ba7c8;
  --color-harbour-blue-500: #478fb4;
  --color-harbour-blue-600: #3d7998;
  --color-harbour-blue-700: #31617a;
  --color-harbour-blue-800: #21485a;
  --color-harbour-blue-900: #16323f;
  --color-harbour-blue-950: #071d28;
}

SCSS

$harbour-blue: #327393;
$harbour-blue-rgb: 50, 115, 147;
$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);
}