#0B4462

CSS

:root {
  --capital-blue: #0b4462;
  --capital-blue-rgb: 11 68 98;
  --capital-blue-oklch: oklch(0.368 0.075 238.1);
}

.element {
  color: var(--capital-blue);
  background-color: hsl(201 80% 21%);
  border-color: oklch(0.368 0.075 238.1);
}

Tailwind CSS v4

@theme {
  --color-capital-blue: #0b4462;
  --color-capital-blue-50: #e3f9ff;
  --color-capital-blue-100: #d2ecff;
  --color-capital-blue-200: #b8d9f2;
  --color-capital-blue-300: #95bddb;
  --color-capital-blue-400: #74a5c6;
  --color-capital-blue-500: #538db2;
  --color-capital-blue-600: #477897;
  --color-capital-blue-700: #396079;
  --color-capital-blue-800: #274659;
  --color-capital-blue-900: #1a313e;
  --color-capital-blue-950: #0a1d27;
}

SCSS

$capital-blue: #0b4462;
$capital-blue-rgb: 11, 68, 98;
$capital-blue-light: mix(#fff, $capital-blue, 20%);
$capital-blue-dark: mix(#000, $capital-blue, 20%);

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