#10374F

CSS

:root {
  --sea-of-stars: #10374f;
  --sea-of-stars-rgb: 16 55 79;
  --sea-of-stars-oklch: oklch(0.322 0.061 239.8);
}

.element {
  color: var(--sea-of-stars);
  background-color: hsl(203 66% 19%);
  border-color: oklch(0.322 0.061 239.8);
}

Tailwind CSS v4

@theme {
  --color-sea-of-stars: #10374f;
  --color-sea-of-stars-50: #e7f8ff;
  --color-sea-of-stars-100: #d7ebfb;
  --color-sea-of-stars-200: #bed8ec;
  --color-sea-of-stars-300: #9dbcd4;
  --color-sea-of-stars-400: #7ea4bf;
  --color-sea-of-stars-500: #608cab;
  --color-sea-of-stars-600: #527690;
  --color-sea-of-stars-700: #415f74;
  --color-sea-of-stars-800: #2e4655;
  --color-sea-of-stars-900: #1f303b;
  --color-sea-of-stars-950: #0f1c25;
}

SCSS

$sea-of-stars: #10374f;
$sea-of-stars-rgb: 16, 55, 79;
$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);
}