#457097

CSS

:root {
  --naval: #457097;
  --naval-rgb: 69 112 151;
  --naval-oklch: oklch(0.531 0.078 247.2);
}

.element {
  color: var(--naval);
  background-color: hsl(209 37% 43%);
  border-color: oklch(0.531 0.078 247.2);
}

Tailwind CSS v4

@theme {
  --color-naval: #457097;
  --color-naval-50: #e5f8ff;
  --color-naval-100: #d5ebff;
  --color-naval-200: #bbd8f5;
  --color-naval-300: #99bbde;
  --color-naval-400: #79a3cb;
  --color-naval-500: #5a8bb7;
  --color-naval-600: #4d769b;
  --color-naval-700: #3d5e7c;
  --color-naval-800: #2a455c;
  --color-naval-900: #1d3040;
  --color-naval-950: #0d1c29;
}

SCSS

$naval: #457097;
$naval-rgb: 69, 112, 151;
$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);
}