#15481E

CSS

:root {
  --realm-of-the-underworld: #15481e;
  --realm-of-the-underworld-rgb: 21 72 30;
  --realm-of-the-underworld-oklch: oklch(0.356 0.088 146.6);
}

.element {
  color: var(--realm-of-the-underworld);
  background-color: hsl(131 55% 18%);
  border-color: oklch(0.356 0.088 146.6);
}

Tailwind CSS v4

@theme {
  --color-realm-of-the-underworld: #15481e;
  --color-realm-of-the-underworld-50: #e5fde8;
  --color-realm-of-the-underworld-100: #d5f1d8;
  --color-realm-of-the-underworld-200: #bbdfc0;
  --color-realm-of-the-underworld-300: #99c49f;
  --color-realm-of-the-underworld-400: #7cad80;
  --color-realm-of-the-underworld-500: #5d9663;
  --color-realm-of-the-underworld-600: #4f7f54;
  --color-realm-of-the-underworld-700: #3f6643;
  --color-realm-of-the-underworld-800: #2e4a2f;
  --color-realm-of-the-underworld-900: #1f3420;
  --color-realm-of-the-underworld-950: #0f1f0f;
}

SCSS

$realm-of-the-underworld: #15481e;
$realm-of-the-underworld-rgb: 21, 72, 30;
$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);
}