#4D6DA1

CSS

:root {
  --song-of-the-sea: #4d6da1;
  --song-of-the-sea-rgb: 77 109 161;
  --song-of-the-sea-oklch: oklch(0.533 0.09 259.8);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(217 35% 47%);
  border-color: oklch(0.533 0.09 259.8);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #4d6da1;
  --color-song-of-the-sea-50: #e7f6ff;
  --color-song-of-the-sea-100: #d8e9ff;
  --color-song-of-the-sea-200: #bfd5fc;
  --color-song-of-the-sea-300: #9eb8e6;
  --color-song-of-the-sea-400: #7fa0d4;
  --color-song-of-the-sea-500: #6287c2;
  --color-song-of-the-sea-600: #5372a4;
  --color-song-of-the-sea-700: #425b83;
  --color-song-of-the-sea-800: #2e4361;
  --color-song-of-the-sea-900: #1f2e44;
  --color-song-of-the-sea-950: #0f1b2c;
}

SCSS

$song-of-the-sea: #4d6da1;
$song-of-the-sea-rgb: 77, 109, 161;
$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);
}