#334B6A

CSS

:root {
  --naval-blue: #334b6a;
  --naval-blue-rgb: 51 75 106;
  --naval-blue-oklch: oklch(0.408 0.06 255.2);
}

.element {
  color: var(--naval-blue);
  background-color: hsl(214 35% 31%);
  border-color: oklch(0.408 0.06 255.2);
}

Tailwind CSS v4

@theme {
  --color-naval-blue: #334b6a;
  --color-naval-blue-50: #ebf6ff;
  --color-naval-blue-100: #dbe9fd;
  --color-naval-blue-200: #c4d6ef;
  --color-naval-blue-300: #a4b9d7;
  --color-naval-blue-400: #87a1c2;
  --color-naval-blue-500: #6b88ae;
  --color-naval-blue-600: #5b7393;
  --color-naval-blue-700: #495c76;
  --color-naval-blue-800: #344457;
  --color-naval-blue-900: #232f3d;
  --color-naval-blue-950: #121b26;
}

SCSS

$naval-blue: #334b6a;
$naval-blue-rgb: 51, 75, 106;
$naval-blue-light: mix(#fff, $naval-blue, 20%);
$naval-blue-dark: mix(#000, $naval-blue, 20%);

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