#3E506C

CSS

:root {
  --naval-blue: #3e506c;
  --naval-blue-rgb: 62 80 108;
  --naval-blue-oklch: oklch(0.428 0.052 259.1);
}

.element {
  color: var(--naval-blue);
  background-color: hsl(217 27% 33%);
  border-color: oklch(0.428 0.052 259.1);
}

Tailwind CSS v4

@theme {
  --color-naval-blue: #3e506c;
  --color-naval-blue-50: #edf6ff;
  --color-naval-blue-100: #dee9fa;
  --color-naval-blue-200: #c8d5eb;
  --color-naval-blue-300: #a9b8d3;
  --color-naval-blue-400: #8ca0be;
  --color-naval-blue-500: #7287a9;
  --color-naval-blue-600: #60738f;
  --color-naval-blue-700: #4d5c73;
  --color-naval-blue-800: #374355;
  --color-naval-blue-900: #262e3b;
  --color-naval-blue-950: #141b25;
}

SCSS

$naval-blue: #3e506c;
$naval-blue-rgb: 62, 80, 108;
$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);
}