#406F9D

CSS

:root {
  --naval: #406f9d;
  --naval-rgb: 64 111 157;
  --naval-oklch: oklch(0.529 0.089 249.4);
}

.element {
  color: var(--naval);
  background-color: hsl(210 42% 43%);
  border-color: oklch(0.529 0.089 249.4);
}

Tailwind CSS v4

@theme {
  --color-naval: #406f9d;
  --color-naval-50: #e3f8ff;
  --color-naval-100: #d3ebff;
  --color-naval-200: #b9d8fa;
  --color-naval-300: #96bbe4;
  --color-naval-400: #75a3d1;
  --color-naval-500: #558abf;
  --color-naval-600: #4975a1;
  --color-naval-700: #3a5e81;
  --color-naval-800: #284560;
  --color-naval-900: #1b3043;
  --color-naval-950: #0b1c2b;
}

SCSS

$naval: #406f9d;
$naval-rgb: 64, 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);
}