#40709C

CSS

:root {
  --naval: #40709c;
  --naval-rgb: 64 112 156;
  --naval-oklch: oklch(0.531 0.087 247.8);
}

.element {
  color: var(--naval);
  background-color: hsl(209 42% 43%);
  border-color: oklch(0.531 0.087 247.8);
}

Tailwind CSS v4

@theme {
  --color-naval: #40709c;
  --color-naval-50: #e3f8ff;
  --color-naval-100: #d3ebff;
  --color-naval-200: #b9d8f9;
  --color-naval-300: #96bbe3;
  --color-naval-400: #74a3d0;
  --color-naval-500: #558bbd;
  --color-naval-600: #4876a0;
  --color-naval-700: #395e80;
  --color-naval-800: #27455f;
  --color-naval-900: #1a3042;
  --color-naval-950: #0b1c2b;
}

SCSS

$naval: #40709c;
$naval-rgb: 64, 112, 156;
$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);
}