#4B71C9

CSS

:root {
  --skies-of-cyberspace: #4b71c9;
  --skies-of-cyberspace-rgb: 75 113 201;
  --skies-of-cyberspace-oklch: oklch(0.564 0.143 264.7);
}

.element {
  color: var(--skies-of-cyberspace);
  background-color: hsl(222 54% 54%);
  border-color: oklch(0.564 0.143 264.7);
}

Tailwind CSS v4

@theme {
  --color-skies-of-cyberspace: #4b71c9;
  --color-skies-of-cyberspace-50: #e2f5ff;
  --color-skies-of-cyberspace-100: #d2e8ff;
  --color-skies-of-cyberspace-200: #b8d3ff;
  --color-skies-of-cyberspace-300: #96b5ff;
  --color-skies-of-cyberspace-400: #749cf3;
  --color-skies-of-cyberspace-500: #5681e4;
  --color-skies-of-cyberspace-600: #496dc0;
  --color-skies-of-cyberspace-700: #3a579a;
  --color-skies-of-cyberspace-800: #274073;
  --color-skies-of-cyberspace-900: #1a2c51;
  --color-skies-of-cyberspace-950: #0b1936;
}

SCSS

$skies-of-cyberspace: #4b71c9;
$skies-of-cyberspace-rgb: 75, 113, 201;
$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);
}