#153F0E

CSS

:root {
  --realm-of-the-underworld: #153f0e;
  --realm-of-the-underworld-rgb: 21 63 14;
  --realm-of-the-underworld-oklch: oklch(0.326 0.09 141);
}

.element {
  color: var(--realm-of-the-underworld);
  background-color: hsl(111 64% 15%);
  border-color: oklch(0.326 0.09 141);
}

Tailwind CSS v4

@theme {
  --color-realm-of-the-underworld: #153f0e;
  --color-realm-of-the-underworld-50: #e7fce5;
  --color-realm-of-the-underworld-100: #d7f0d5;
  --color-realm-of-the-underworld-200: #bfdfbc;
  --color-realm-of-the-underworld-300: #9dc49a;
  --color-realm-of-the-underworld-400: #81ac7a;
  --color-realm-of-the-underworld-500: #64955c;
  --color-realm-of-the-underworld-600: #557e4e;
  --color-realm-of-the-underworld-700: #44653e;
  --color-realm-of-the-underworld-800: #324a2b;
  --color-realm-of-the-underworld-900: #22331d;
  --color-realm-of-the-underworld-950: #111f0d;
}

SCSS

$realm-of-the-underworld: #153f0e;
$realm-of-the-underworld-rgb: 21, 63, 14;
$realm-of-the-underworld-light: mix(#fff, $realm-of-the-underworld, 20%);
$realm-of-the-underworld-dark: mix(#000, $realm-of-the-underworld, 20%);

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