#2D7398

CSS

:root {
  --harbour-blue: #2d7398;
  --harbour-blue-rgb: 45 115 152;
  --harbour-blue-oklch: oklch(0.528 0.09 235.3);
}

.element {
  color: var(--harbour-blue);
  background-color: hsl(201 54% 39%);
  border-color: oklch(0.528 0.09 235.3);
}

Tailwind CSS v4

@theme {
  --color-harbour-blue: #2d7398;
  --color-harbour-blue-50: #defaff;
  --color-harbour-blue-100: #cdedff;
  --color-harbour-blue-200: #b1dbf7;
  --color-harbour-blue-300: #8bbfe0;
  --color-harbour-blue-400: #67a7cc;
  --color-harbour-blue-500: #418fba;
  --color-harbour-blue-600: #39799d;
  --color-harbour-blue-700: #2d617e;
  --color-harbour-blue-800: #1e475d;
  --color-harbour-blue-900: #143241;
  --color-harbour-blue-950: #051d29;
}

SCSS

$harbour-blue: #2d7398;
$harbour-blue-rgb: 45, 115, 152;
$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);
}