#426DAB

CSS

:root {
  --song-of-the-sea: #426dab;
  --song-of-the-sea-rgb: 66 109 171;
  --song-of-the-sea-oklch: oklch(0.533 0.109 257.6);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(215 44% 46%);
  border-color: oklch(0.533 0.109 257.6);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #426dab;
  --color-song-of-the-sea-50: #e3f7ff;
  --color-song-of-the-sea-100: #d3e9ff;
  --color-song-of-the-sea-200: #b9d6ff;
  --color-song-of-the-sea-300: #96b9f0;
  --color-song-of-the-sea-400: #75a0df;
  --color-song-of-the-sea-500: #5687ce;
  --color-song-of-the-sea-600: #4972ad;
  --color-song-of-the-sea-700: #3a5b8b;
  --color-song-of-the-sea-800: #274367;
  --color-song-of-the-sea-900: #1a2f49;
  --color-song-of-the-sea-950: #0b1b30;
}

SCSS

$song-of-the-sea: #426dab;
$song-of-the-sea-rgb: 66, 109, 171;
$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);
}