#5077A7

CSS

:root {
  --song-of-the-sea: #5077a7;
  --song-of-the-sea-rgb: 80 119 167;
  --song-of-the-sea-oklch: oklch(0.561 0.087 254.2);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(213 35% 48%);
  border-color: oklch(0.561 0.087 254.2);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #5077a7;
  --color-song-of-the-sea-50: #e5f7ff;
  --color-song-of-the-sea-100: #d6eaff;
  --color-song-of-the-sea-200: #bdd6fa;
  --color-song-of-the-sea-300: #9bbae4;
  --color-song-of-the-sea-400: #7ba1d1;
  --color-song-of-the-sea-500: #5d89bf;
  --color-song-of-the-sea-600: #4f74a1;
  --color-song-of-the-sea-700: #3f5d81;
  --color-song-of-the-sea-800: #2c4460;
  --color-song-of-the-sea-900: #1d2f43;
  --color-song-of-the-sea-950: #0d1b2b;
}

SCSS

$song-of-the-sea: #5077a7;
$song-of-the-sea-rgb: 80, 119, 167;
$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);
}