#163658

CSS

:root {
  --beyond-the-stars: #163658;
  --beyond-the-stars-rgb: 22 54 88;
  --beyond-the-stars-oklch: oklch(0.327 0.071 252.1);
}

.element {
  color: var(--beyond-the-stars);
  background-color: hsl(211 60% 22%);
  border-color: oklch(0.327 0.071 252.1);
}

Tailwind CSS v4

@theme {
  --color-beyond-the-stars: #163658;
  --color-beyond-the-stars-50: #e8f7ff;
  --color-beyond-the-stars-100: #d8eaff;
  --color-beyond-the-stars-200: #c0d7f3;
  --color-beyond-the-stars-300: #9fbadc;
  --color-beyond-the-stars-400: #80a2c8;
  --color-beyond-the-stars-500: #6389b5;
  --color-beyond-the-stars-600: #547498;
  --color-beyond-the-stars-700: #435d7a;
  --color-beyond-the-stars-800: #2f445a;
  --color-beyond-the-stars-900: #202f3f;
  --color-beyond-the-stars-950: #0f1c28;
}

SCSS

$beyond-the-stars: #163658;
$beyond-the-stars-rgb: 22, 54, 88;
$beyond-the-stars-light: mix(#fff, $beyond-the-stars, 20%);
$beyond-the-stars-dark: mix(#000, $beyond-the-stars, 20%);

.element {
  color: $beyond-the-stars;
  box-shadow: 0 0 0 2px rgba($beyond-the-stars, 0.35);
}