#111235

CSS

:root {
  --infinite-night: #111235;
  --infinite-night-rgb: 17 18 53;
  --infinite-night-oklch: oklch(0.206 0.067 277.5);
}

.element {
  color: var(--infinite-night);
  background-color: hsl(238 51% 14%);
  border-color: oklch(0.206 0.067 277.5);
}

Tailwind CSS v4

@theme {
  --color-infinite-night: #111235;
  --color-infinite-night-50: #f1f4ff;
  --color-infinite-night-100: #e3e6ff;
  --color-infinite-night-200: #ced2f1;
  --color-infinite-night-300: #b0b4da;
  --color-infinite-night-400: #949bc6;
  --color-infinite-night-500: #7b82b3;
  --color-infinite-night-600: #686e97;
  --color-infinite-night-700: #535879;
  --color-infinite-night-800: #3c415a;
  --color-infinite-night-900: #292d3f;
  --color-infinite-night-950: #171928;
}

SCSS

$infinite-night: #111235;
$infinite-night-rgb: 17, 18, 53;
$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);
}