#4971CD

CSS

:root {
  --skies-of-cyberspace: #4971cd;
  --skies-of-cyberspace-rgb: 73 113 205;
  --skies-of-cyberspace-oklch: oklch(0.566 0.149 264.5);
}

.element {
  color: var(--skies-of-cyberspace);
  background-color: hsl(222 57% 55%);
  border-color: oklch(0.566 0.149 264.5);
}

Tailwind CSS v4

@theme {
  --color-skies-of-cyberspace: #4971cd;
  --color-skies-of-cyberspace-50: #e2f5ff;
  --color-skies-of-cyberspace-100: #d1e8ff;
  --color-skies-of-cyberspace-200: #b7d3ff;
  --color-skies-of-cyberspace-300: #94b5ff;
  --color-skies-of-cyberspace-400: #729bf6;
  --color-skies-of-cyberspace-500: #5380e8;
  --color-skies-of-cyberspace-600: #476dc3;
  --color-skies-of-cyberspace-700: #38579d;
  --color-skies-of-cyberspace-800: #254075;
  --color-skies-of-cyberspace-900: #192c53;
  --color-skies-of-cyberspace-950: #0a1938;
}

SCSS

$skies-of-cyberspace: #4971cd;
$skies-of-cyberspace-rgb: 73, 113, 205;
$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);
}