#4B73CC

CSS

:root {
  --skies-of-cyberspace: #4b73cc;
  --skies-of-cyberspace-rgb: 75 115 204;
  --skies-of-cyberspace-oklch: oklch(0.571 0.145 264.1);
}

.element {
  color: var(--skies-of-cyberspace);
  background-color: hsl(221 56% 55%);
  border-color: oklch(0.571 0.145 264.1);
}

Tailwind CSS v4

@theme {
  --color-skies-of-cyberspace: #4b73cc;
  --color-skies-of-cyberspace-50: #e2f5ff;
  --color-skies-of-cyberspace-100: #d1e8ff;
  --color-skies-of-cyberspace-200: #b7d3ff;
  --color-skies-of-cyberspace-300: #95b5ff;
  --color-skies-of-cyberspace-400: #739cf4;
  --color-skies-of-cyberspace-500: #5481e5;
  --color-skies-of-cyberspace-600: #486dc1;
  --color-skies-of-cyberspace-700: #39589b;
  --color-skies-of-cyberspace-800: #264074;
  --color-skies-of-cyberspace-900: #192c52;
  --color-skies-of-cyberspace-950: #0a1937;
}

SCSS

$skies-of-cyberspace: #4b73cc;
$skies-of-cyberspace-rgb: 75, 115, 204;
$skies-of-cyberspace-light: mix(#fff, $skies-of-cyberspace, 20%);
$skies-of-cyberspace-dark: mix(#000, $skies-of-cyberspace, 20%);

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