#193F51

CSS

:root {
  --capital-blue: #193f51;
  --capital-blue-rgb: 25 63 81;
  --capital-blue-oklch: oklch(0.349 0.053 231.6);
}

.element {
  color: var(--capital-blue);
  background-color: hsl(199 53% 21%);
  border-color: oklch(0.349 0.053 231.6);
}

Tailwind CSS v4

@theme {
  --color-capital-blue: #193f51;
  --color-capital-blue-50: #e7f8ff;
  --color-capital-blue-100: #d7ebf7;
  --color-capital-blue-200: #bfd9e8;
  --color-capital-blue-300: #9dbdcf;
  --color-capital-blue-400: #7fa5b9;
  --color-capital-blue-500: #628da3;
  --color-capital-blue-600: #53778a;
  --color-capital-blue-700: #425f6f;
  --color-capital-blue-800: #2f4651;
  --color-capital-blue-900: #203039;
  --color-capital-blue-950: #0f1d23;
}

SCSS

$capital-blue: #193f51;
$capital-blue-rgb: 25, 63, 81;
$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);
}