The Vast of Night

CSS

:root {
  --the-vast-of-night: #110066;
  --the-vast-of-night-rgb: 17 0 102;
  --the-vast-of-night-oklch: oklch(0.24 0.154 272.3);
}

.element {
  color: var(--the-vast-of-night);
  background-color: hsl(250 100% 20%);
  border-color: oklch(0.24 0.154 272.3);
}

Tailwind CSS v4

@theme {
  --color-the-vast-of-night: #110066;
  --color-the-vast-of-night-50: #e7f3ff;
  --color-the-vast-of-night-100: #d8e5ff;
  --color-the-vast-of-night-200: #c0d0ff;
  --color-the-vast-of-night-300: #9fb1ff;
  --color-the-vast-of-night-400: #8096f9;
  --color-the-vast-of-night-500: #657beb;
  --color-the-vast-of-night-600: #5568c6;
  --color-the-vast-of-night-700: #44539f;
  --color-the-vast-of-night-800: #2e3d77;
  --color-the-vast-of-night-900: #1f2a54;
  --color-the-vast-of-night-950: #0f1739;
}

SCSS

$the-vast-of-night: #110066;
$the-vast-of-night-rgb: 17, 0, 102;
$the-vast-of-night-light: mix(#fff, $the-vast-of-night, 20%);
$the-vast-of-night-dark: mix(#000, $the-vast-of-night, 20%);

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