#131435

CSS

:root {
  --infinite-night: #131435;
  --infinite-night-rgb: 19 20 53;
  --infinite-night-oklch: oklch(0.212 0.063 278.2);
}

.element {
  color: var(--infinite-night);
  background-color: hsl(238 47% 14%);
  border-color: oklch(0.212 0.063 278.2);
}

Tailwind CSS v4

@theme {
  --color-infinite-night: #131435;
  --color-infinite-night-50: #f1f4ff;
  --color-infinite-night-100: #e3e6fd;
  --color-infinite-night-200: #ced2f0;
  --color-infinite-night-300: #b1b4d8;
  --color-infinite-night-400: #959bc4;
  --color-infinite-night-500: #7c82b0;
  --color-infinite-night-600: #696e95;
  --color-infinite-night-700: #545877;
  --color-infinite-night-800: #3c4158;
  --color-infinite-night-900: #292d3e;
  --color-infinite-night-950: #171a27;
}

SCSS

$infinite-night: #131435;
$infinite-night-rgb: 19, 20, 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);
}