Copenhagen Blue

CSS

:root {
  --copenhagen-blue: #21638b;
  --copenhagen-blue-rgb: 33 99 139;
  --copenhagen-blue-oklch: oklch(0.478 0.092 239.7);
}

.element {
  color: var(--copenhagen-blue);
  background-color: hsl(203 62% 34%);
  border-color: oklch(0.478 0.092 239.7);
}

Tailwind CSS v4

@theme {
  --color-copenhagen-blue: #21638b;
  --color-copenhagen-blue-50: #dff9ff;
  --color-copenhagen-blue-100: #ceecff;
  --color-copenhagen-blue-200: #b2daf9;
  --color-copenhagen-blue-300: #8ebee3;
  --color-copenhagen-blue-400: #6aa6cf;
  --color-copenhagen-blue-500: #468ebd;
  --color-copenhagen-blue-600: #3c789f;
  --color-copenhagen-blue-700: #306080;
  --color-copenhagen-blue-800: #20475e;
  --color-copenhagen-blue-900: #153142;
  --color-copenhagen-blue-950: #061d2a;
}

SCSS

$copenhagen-blue: #21638b;
$copenhagen-blue-rgb: 33, 99, 139;
$copenhagen-blue-light: mix(#fff, $copenhagen-blue, 20%);
$copenhagen-blue-dark: mix(#000, $copenhagen-blue, 20%);

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