#506D9D

CSS

:root {
  --song-of-the-sea: #506d9d;
  --song-of-the-sea-rgb: 80 109 157;
  --song-of-the-sea-oklch: oklch(0.533 0.083 260.2);
}

.element {
  color: var(--song-of-the-sea);
  background-color: hsl(217 32% 46%);
  border-color: oklch(0.533 0.083 260.2);
}

Tailwind CSS v4

@theme {
  --color-song-of-the-sea: #506d9d;
  --color-song-of-the-sea-50: #e8f6ff;
  --color-song-of-the-sea-100: #d9e9ff;
  --color-song-of-the-sea-200: #c1d5f9;
  --color-song-of-the-sea-300: #a0b8e3;
  --color-song-of-the-sea-400: #829fd0;
  --color-song-of-the-sea-500: #6687bd;
  --color-song-of-the-sea-600: #5672a0;
  --color-song-of-the-sea-700: #455b80;
  --color-song-of-the-sea-800: #30435f;
  --color-song-of-the-sea-900: #212e43;
  --color-song-of-the-sea-950: #101b2b;
}

SCSS

$song-of-the-sea: #506d9d;
$song-of-the-sea-rgb: 80, 109, 157;
$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);
}