#05153D

CSS

:root {
  --infinite-night: #05153d;
  --infinite-night-rgb: 5 21 61;
  --infinite-night-oklch: oklch(0.213 0.08 263.6);
}

.element {
  color: var(--infinite-night);
  background-color: hsl(223 85% 13%);
  border-color: oklch(0.213 0.08 263.6);
}

Tailwind CSS v4

@theme {
  --color-infinite-night: #05153d;
  --color-infinite-night-50: #eaf5ff;
  --color-infinite-night-100: #dbe8ff;
  --color-infinite-night-200: #c4d4f8;
  --color-infinite-night-300: #a4b7e1;
  --color-infinite-night-400: #869ecf;
  --color-infinite-night-500: #6a86bc;
  --color-infinite-night-600: #5a719f;
  --color-infinite-night-700: #485b7f;
  --color-infinite-night-800: #33425e;
  --color-infinite-night-900: #232e42;
  --color-infinite-night-950: #121b2a;
}

SCSS

$infinite-night: #05153d;
$infinite-night-rgb: 5, 21, 61;
$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);
}