#436BB5

CSS

:root {
  --song-of-the-sea: #436bb5;
  --song-of-the-sea-rgb: 67 107 181;
  --song-of-the-sea-oklch: oklch(0.535 0.125 261.7);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(219 46% 49%);
  border-color: oklch(0.535 0.125 261.7);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #436bb5;
  --color-song-of-the-sea-50: #e3f6ff;
  --color-song-of-the-sea-100: #d3e8ff;
  --color-song-of-the-sea-200: #b9d5ff;
  --color-song-of-the-sea-300: #96b7f8;
  --color-song-of-the-sea-400: #759ee8;
  --color-song-of-the-sea-500: #5684d8;
  --color-song-of-the-sea-600: #4a70b6;
  --color-song-of-the-sea-700: #3a5a93;
  --color-song-of-the-sea-800: #27426d;
  --color-song-of-the-sea-900: #1a2e4d;
  --color-song-of-the-sea-950: #0b1a33;
}

SCSS

$song-of-the-sea: #436bb5;
$song-of-the-sea-rgb: 67, 107, 181;
$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);
}