#466DA4

CSS

:root {
  --song-of-the-sea: #466da4;
  --song-of-the-sea-rgb: 70 109 164;
  --song-of-the-sea-oklch: oklch(0.531 0.098 257.1);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(215 40% 46%);
  border-color: oklch(0.531 0.098 257.1);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #466da4;
  --color-song-of-the-sea-50: #e5f7ff;
  --color-song-of-the-sea-100: #d5e9ff;
  --color-song-of-the-sea-200: #bcd6ff;
  --color-song-of-the-sea-300: #9ab9ea;
  --color-song-of-the-sea-400: #79a0d8;
  --color-song-of-the-sea-500: #5b87c6;
  --color-song-of-the-sea-600: #4e73a7;
  --color-song-of-the-sea-700: #3e5c86;
  --color-song-of-the-sea-800: #2a4464;
  --color-song-of-the-sea-900: #1c2f46;
  --color-song-of-the-sea-950: #0d1b2d;
}

SCSS

$song-of-the-sea: #466da4;
$song-of-the-sea-rgb: 70, 109, 164;
$song-of-the-sea-light: mix(#fff, $song-of-the-sea, 20%);
$song-of-the-sea-dark: mix(#000, $song-of-the-sea, 20%);

.element {
  color: $song-of-the-sea;
  box-shadow: 0 0 0 2px rgba($song-of-the-sea, 0.35);
}