#5172BE

CSS

:root {
  --song-of-the-sea: #5172be;
  --song-of-the-sea-rgb: 81 114 190;
  --song-of-the-sea-oklch: oklch(0.563 0.124 265);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(222 46% 53%);
  border-color: oklch(0.563 0.124 265);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #5172be;
  --color-song-of-the-sea-50: #e5f5ff;
  --color-song-of-the-sea-100: #d5e8ff;
  --color-song-of-the-sea-200: #bcd3ff;
  --color-song-of-the-sea-300: #9bb6f8;
  --color-song-of-the-sea-400: #7a9ce8;
  --color-song-of-the-sea-500: #5d82d8;
  --color-song-of-the-sea-600: #4f6fb6;
  --color-song-of-the-sea-700: #3f5892;
  --color-song-of-the-sea-800: #2b416d;
  --color-song-of-the-sea-900: #1d2d4d;
  --color-song-of-the-sea-950: #0d1a33;
}

SCSS

$song-of-the-sea: #5172be;
$song-of-the-sea-rgb: 81, 114, 190;
$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);
}