#0D1536

CSS

:root {
  --infinite-night: #0d1536;
  --infinite-night-rgb: 13 21 54;
  --infinite-night-oklch: oklch(0.211 0.065 269.7);
}

.element {
  color: var(--infinite-night);
  background-color: hsl(228 61% 13%);
  border-color: oklch(0.211 0.065 269.7);
}

Tailwind CSS v4

@theme {
  --color-infinite-night: #0d1536;
  --color-infinite-night-50: #eef5ff;
  --color-infinite-night-100: #e0e7ff;
  --color-infinite-night-200: #cad3f1;
  --color-infinite-night-300: #abb6da;
  --color-infinite-night-400: #8f9dc6;
  --color-infinite-night-500: #7584b2;
  --color-infinite-night-600: #637097;
  --color-infinite-night-700: #4f5a79;
  --color-infinite-night-800: #384259;
  --color-infinite-night-900: #272d3f;
  --color-infinite-night-950: #151a28;
}

SCSS

$infinite-night: #0d1536;
$infinite-night-rgb: 13, 21, 54;
$infinite-night-light: mix(#fff, $infinite-night, 20%);
$infinite-night-dark: mix(#000, $infinite-night, 20%);

.element {
  color: $infinite-night;
  box-shadow: 0 0 0 2px rgba($infinite-night, 0.35);
}