#436F9D

CSS

:root {
  --naval: #436f9d;
  --naval-rgb: 67 111 157;
  --naval-oklch: oklch(0.53 0.088 250.8);
}

.element {
  color: var(--naval);
  background-color: hsl(211 40% 44%);
  border-color: oklch(0.53 0.088 250.8);
}

Tailwind CSS v4

@theme {
  --color-naval: #436f9d;
  --color-naval-50: #e4f7ff;
  --color-naval-100: #d4eaff;
  --color-naval-200: #bad7fa;
  --color-naval-300: #98bbe4;
  --color-naval-400: #77a2d1;
  --color-naval-500: #588abe;
  --color-naval-600: #4b75a1;
  --color-naval-700: #3c5d81;
  --color-naval-800: #29455f;
  --color-naval-900: #1c3043;
  --color-naval-950: #0c1c2b;
}

SCSS

$naval: #436f9d;
$naval-rgb: 67, 111, 157;
$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);
}