#4272CB

CSS

:root {
  --skies-of-cyberspace: #4272cb;
  --skies-of-cyberspace-rgb: 66 114 203;
  --skies-of-cyberspace-oklch: oklch(0.564 0.147 261.6);
}

.element {
  color: var(--skies-of-cyberspace);
  background-color: hsl(219 57% 53%);
  border-color: oklch(0.564 0.147 261.6);
}

Tailwind CSS v4

@theme {
  --color-skies-of-cyberspace: #4272cb;
  --color-skies-of-cyberspace-50: #e0f6ff;
  --color-skies-of-cyberspace-100: #cfe8ff;
  --color-skies-of-cyberspace-200: #b4d4ff;
  --color-skies-of-cyberspace-300: #90b6ff;
  --color-skies-of-cyberspace-400: #6c9df5;
  --color-skies-of-cyberspace-500: #4c82e7;
  --color-skies-of-cyberspace-600: #416ec2;
  --color-skies-of-cyberspace-700: #34589c;
  --color-skies-of-cyberspace-800: #214175;
  --color-skies-of-cyberspace-900: #162d52;
  --color-skies-of-cyberspace-950: #071937;
}

SCSS

$skies-of-cyberspace: #4272cb;
$skies-of-cyberspace-rgb: 66, 114, 203;
$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);
}