#4E6D9F

CSS

:root {
  --song-of-the-sea: #4e6d9f;
  --song-of-the-sea-rgb: 78 109 159;
  --song-of-the-sea-oklch: oklch(0.533 0.087 259.7);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(217 34% 46%);
  border-color: oklch(0.533 0.087 259.7);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #4e6d9f;
  --color-song-of-the-sea-50: #e8f6ff;
  --color-song-of-the-sea-100: #d8e9ff;
  --color-song-of-the-sea-200: #c0d5fa;
  --color-song-of-the-sea-300: #9fb8e5;
  --color-song-of-the-sea-400: #80a0d2;
  --color-song-of-the-sea-500: #6387c0;
  --color-song-of-the-sea-600: #5472a2;
  --color-song-of-the-sea-700: #435b82;
  --color-song-of-the-sea-800: #2f4360;
  --color-song-of-the-sea-900: #202e44;
  --color-song-of-the-sea-950: #0f1b2c;
}

SCSS

$song-of-the-sea: #4e6d9f;
$song-of-the-sea-rgb: 78, 109, 159;
$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);
}