#4A71CC

CSS

:root {
  --skies-of-cyberspace: #4a71cc;
  --skies-of-cyberspace-rgb: 74 113 204;
  --skies-of-cyberspace-oklch: oklch(0.566 0.147 264.7);
}

.element {
  color: var(--skies-of-cyberspace);
  background-color: hsl(222 56% 55%);
  border-color: oklch(0.566 0.147 264.7);
}

Tailwind CSS v4

@theme {
  --color-skies-of-cyberspace: #4a71cc;
  --color-skies-of-cyberspace-50: #e2f5ff;
  --color-skies-of-cyberspace-100: #d1e7ff;
  --color-skies-of-cyberspace-200: #b8d3ff;
  --color-skies-of-cyberspace-300: #95b5ff;
  --color-skies-of-cyberspace-400: #739bf5;
  --color-skies-of-cyberspace-500: #5480e7;
  --color-skies-of-cyberspace-600: #486dc3;
  --color-skies-of-cyberspace-700: #39579c;
  --color-skies-of-cyberspace-800: #264075;
  --color-skies-of-cyberspace-900: #192c52;
  --color-skies-of-cyberspace-950: #0a1937;
}

SCSS

$skies-of-cyberspace: #4a71cc;
$skies-of-cyberspace-rgb: 74, 113, 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);
}