#4B6DA3

CSS

:root {
  --song-of-the-sea: #4b6da3;
  --song-of-the-sea-rgb: 75 109 163;
  --song-of-the-sea-oklch: oklch(0.533 0.094 259.3);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(217 37% 47%);
  border-color: oklch(0.533 0.094 259.3);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #4b6da3;
  --color-song-of-the-sea-50: #e6f6ff;
  --color-song-of-the-sea-100: #d7e9ff;
  --color-song-of-the-sea-200: #bed5fd;
  --color-song-of-the-sea-300: #9db8e8;
  --color-song-of-the-sea-400: #7da0d6;
  --color-song-of-the-sea-500: #6087c4;
  --color-song-of-the-sea-600: #5272a6;
  --color-song-of-the-sea-700: #415b85;
  --color-song-of-the-sea-800: #2d4363;
  --color-song-of-the-sea-900: #1e2e45;
  --color-song-of-the-sea-950: #0e1b2d;
}

SCSS

$song-of-the-sea: #4b6da3;
$song-of-the-sea-rgb: 75, 109, 163;
$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);
}