#387293

CSS

:root {
  --harbour-blue: #387293;
  --harbour-blue-rgb: 56 114 147;
  --harbour-blue-oklch: oklch(0.527 0.08 236);
}

.element {
  color: var(--harbour-blue);
  background-color: hsl(202 45% 40%);
  border-color: oklch(0.527 0.08 236);
}

Tailwind CSS v4

@theme {
  --color-harbour-blue: #387293;
  --color-harbour-blue-50: #e1f9ff;
  --color-harbour-blue-100: #d0ecff;
  --color-harbour-blue-200: #b5daf3;
  --color-harbour-blue-300: #91bedc;
  --color-harbour-blue-400: #6fa6c8;
  --color-harbour-blue-500: #4d8eb4;
  --color-harbour-blue-600: #427898;
  --color-harbour-blue-700: #35607a;
  --color-harbour-blue-800: #24475a;
  --color-harbour-blue-900: #18313f;
  --color-harbour-blue-950: #081d28;
}

SCSS

$harbour-blue: #387293;
$harbour-blue-rgb: 56, 114, 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);
}