#163246

CSS

:root {
  --sea-of-stars: #163246;
  --sea-of-stars-rgb: 22 50 70;
  --sea-of-stars-oklch: oklch(0.305 0.05 241.9);
}

.element {
  color: var(--sea-of-stars);
  background-color: hsl(205 52% 18%);
  border-color: oklch(0.305 0.05 241.9);
}

Tailwind CSS v4

@theme {
  --color-sea-of-stars: #163246;
  --color-sea-of-stars-50: #eaf7ff;
  --color-sea-of-stars-100: #dbeaf8;
  --color-sea-of-stars-200: #c3d7e8;
  --color-sea-of-stars-300: #a3bbcf;
  --color-sea-of-stars-400: #85a3ba;
  --color-sea-of-stars-500: #698ba5;
  --color-sea-of-stars-600: #59758b;
  --color-sea-of-stars-700: #475e70;
  --color-sea-of-stars-800: #334552;
  --color-sea-of-stars-900: #223039;
  --color-sea-of-stars-950: #111c23;
}

SCSS

$sea-of-stars: #163246;
$sea-of-stars-rgb: 22, 50, 70;
$sea-of-stars-light: mix(#fff, $sea-of-stars, 20%);
$sea-of-stars-dark: mix(#000, $sea-of-stars, 20%);

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