#4F71D2

CSS

:root {
  --skies-of-cyberspace: #4f71d2;
  --skies-of-cyberspace-rgb: 79 113 210;
  --skies-of-cyberspace-oklch: oklch(0.572 0.154 267);
}

.element {
  color: var(--skies-of-cyberspace);
  background-color: hsl(224 59% 57%);
  border-color: oklch(0.572 0.154 267);
}

Tailwind CSS v4

@theme {
  --color-skies-of-cyberspace: #4f71d2;
  --color-skies-of-cyberspace-50: #e3f4ff;
  --color-skies-of-cyberspace-100: #d3e7ff;
  --color-skies-of-cyberspace-200: #b9d2ff;
  --color-skies-of-cyberspace-300: #97b4ff;
  --color-skies-of-cyberspace-400: #7599f9;
  --color-skies-of-cyberspace-500: #587eeb;
  --color-skies-of-cyberspace-600: #4b6bc6;
  --color-skies-of-cyberspace-700: #3c569f;
  --color-skies-of-cyberspace-800: #283f77;
  --color-skies-of-cyberspace-900: #1a2b54;
  --color-skies-of-cyberspace-950: #0b1839;
}

SCSS

$skies-of-cyberspace: #4f71d2;
$skies-of-cyberspace-rgb: 79, 113, 210;
$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);
}