#4B71D6

CSS

:root {
  --skies-of-cyberspace: #4b71d6;
  --skies-of-cyberspace-rgb: 75 113 214;
  --skies-of-cyberspace-oklch: oklch(0.573 0.161 266);
}

.element {
  color: var(--skies-of-cyberspace);
  background-color: hsl(224 63% 57%);
  border-color: oklch(0.573 0.161 266);
}

Tailwind CSS v4

@theme {
  --color-skies-of-cyberspace: #4b71d6;
  --color-skies-of-cyberspace-50: #e1f5ff;
  --color-skies-of-cyberspace-100: #d1e7ff;
  --color-skies-of-cyberspace-200: #b7d2ff;
  --color-skies-of-cyberspace-300: #94b4ff;
  --color-skies-of-cyberspace-400: #719afd;
  --color-skies-of-cyberspace-500: #537eef;
  --color-skies-of-cyberspace-600: #476bca;
  --color-skies-of-cyberspace-700: #3855a2;
  --color-skies-of-cyberspace-800: #253f79;
  --color-skies-of-cyberspace-900: #182b56;
  --color-skies-of-cyberspace-950: #0a183a;
}

SCSS

$skies-of-cyberspace: #4b71d6;
$skies-of-cyberspace-rgb: 75, 113, 214;
$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);
}