#5075B2

CSS

:root {
  --song-of-the-sea: #5075b2;
  --song-of-the-sea-rgb: 80 117 178;
  --song-of-the-sea-oklch: oklch(0.562 0.104 260);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(217 39% 51%);
  border-color: oklch(0.562 0.104 260);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #5075b2;
  --color-song-of-the-sea-50: #e5f6ff;
  --color-song-of-the-sea-100: #d5e9ff;
  --color-song-of-the-sea-200: #bcd5ff;
  --color-song-of-the-sea-300: #9ab8ed;
  --color-song-of-the-sea-400: #7a9fdc;
  --color-song-of-the-sea-500: #5c86cb;
  --color-song-of-the-sea-600: #4f72ab;
  --color-song-of-the-sea-700: #3f5b89;
  --color-song-of-the-sea-800: #2b4366;
  --color-song-of-the-sea-900: #1d2e48;
  --color-song-of-the-sea-950: #0d1b2f;
}

SCSS

$song-of-the-sea: #5075b2;
$song-of-the-sea-rgb: 80, 117, 178;
$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);
}