#406FA0

CSS

:root {
  --naval: #406fa0;
  --naval-rgb: 64 111 160;
  --naval-oklch: oklch(0.53 0.093 250.9);
}

.element {
  color: var(--naval);
  background-color: hsl(211 43% 44%);
  border-color: oklch(0.53 0.093 250.9);
}

Tailwind CSS v4

@theme {
  --color-naval: #406fa0;
  --color-naval-50: #e3f7ff;
  --color-naval-100: #d3ebff;
  --color-naval-200: #b9d7fc;
  --color-naval-300: #96bbe7;
  --color-naval-400: #74a2d4;
  --color-naval-500: #558ac2;
  --color-naval-600: #4875a4;
  --color-naval-700: #395d83;
  --color-naval-800: #274561;
  --color-naval-900: #1a3044;
  --color-naval-950: #0b1c2c;
}

SCSS

$naval: #406fa0;
$naval-rgb: 64, 111, 160;
$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);
}