#4E6DAF

CSS

:root {
  --song-of-the-sea: #4e6daf;
  --song-of-the-sea-rgb: 78 109 175;
  --song-of-the-sea-oklch: oklch(0.542 0.11 264);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(221 38% 50%);
  border-color: oklch(0.542 0.11 264);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #4e6daf;
  --color-song-of-the-sea-50: #e6f5ff;
  --color-song-of-the-sea-100: #d7e8ff;
  --color-song-of-the-sea-200: #bed4ff;
  --color-song-of-the-sea-300: #9db7f1;
  --color-song-of-the-sea-400: #7d9de0;
  --color-song-of-the-sea-500: #6184cf;
  --color-song-of-the-sea-600: #5270af;
  --color-song-of-the-sea-700: #41598c;
  --color-song-of-the-sea-800: #2d4268;
  --color-song-of-the-sea-900: #1e2d49;
  --color-song-of-the-sea-950: #0e1a30;
}

SCSS

$song-of-the-sea: #4e6daf;
$song-of-the-sea-rgb: 78, 109, 175;
$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);
}