#3D6FA5

CSS

:root {
  --naval: #3d6fa5;
  --naval-rgb: 61 111 165;
  --naval-oklch: oklch(0.532 0.101 251.9);
}

.element {
  color: var(--naval);
  background-color: hsl(211 46% 44%);
  border-color: oklch(0.532 0.101 251.9);
}

Tailwind CSS v4

@theme {
  --color-naval: #3d6fa5;
  --color-naval-50: #e2f7ff;
  --color-naval-100: #d1ebff;
  --color-naval-200: #b7d7ff;
  --color-naval-300: #93bbeb;
  --color-naval-400: #71a2d9;
  --color-naval-500: #518ac7;
  --color-naval-600: #4574a8;
  --color-naval-700: #375d87;
  --color-naval-800: #254564;
  --color-naval-900: #192f46;
  --color-naval-950: #091c2e;
}

SCSS

$naval: #3d6fa5;
$naval-rgb: 61, 111, 165;
$naval-light: mix(#fff, $naval, 20%);
$naval-dark: mix(#000, $naval, 20%);

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