#4273D7

CSS

:root {
  --skies-of-cyberspace: #4273d7;
  --skies-of-cyberspace-rgb: 66 115 215;
  --skies-of-cyberspace-oklch: oklch(0.574 0.163 262.7);
}

.element {
  color: var(--skies-of-cyberspace);
  background-color: hsl(220 65% 55%);
  border-color: oklch(0.574 0.163 262.7);
}

Tailwind CSS v4

@theme {
  --color-skies-of-cyberspace: #4273d7;
  --color-skies-of-cyberspace-50: #def5ff;
  --color-skies-of-cyberspace-100: #cde8ff;
  --color-skies-of-cyberspace-200: #b2d4ff;
  --color-skies-of-cyberspace-300: #8eb5ff;
  --color-skies-of-cyberspace-400: #6a9bfe;
  --color-skies-of-cyberspace-500: #4980f0;
  --color-skies-of-cyberspace-600: #3e6dcb;
  --color-skies-of-cyberspace-700: #3257a3;
  --color-skies-of-cyberspace-800: #1f407a;
  --color-skies-of-cyberspace-900: #142c56;
  --color-skies-of-cyberspace-950: #06193a;
}

SCSS

$skies-of-cyberspace: #4273d7;
$skies-of-cyberspace-rgb: 66, 115, 215;
$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);
}