#124309

CSS

:root {
  --realm-of-the-underworld: #124309;
  --realm-of-the-underworld-rgb: 18 67 9;
  --realm-of-the-underworld-oklch: oklch(0.337 0.1 141);
}

.element {
  color: var(--realm-of-the-underworld);
  background-color: hsl(111 76% 15%);
  border-color: oklch(0.337 0.1 141);
}

Tailwind CSS v4

@theme {
  --color-realm-of-the-underworld: #124309;
  --color-realm-of-the-underworld-50: #e5fde3;
  --color-realm-of-the-underworld-100: #d5f1d3;
  --color-realm-of-the-underworld-200: #bce0b9;
  --color-realm-of-the-underworld-300: #99c596;
  --color-realm-of-the-underworld-400: #7dad75;
  --color-realm-of-the-underworld-500: #5f9756;
  --color-realm-of-the-underworld-600: #517f49;
  --color-realm-of-the-underworld-700: #41663a;
  --color-realm-of-the-underworld-800: #304b28;
  --color-realm-of-the-underworld-900: #20341b;
  --color-realm-of-the-underworld-950: #101f0b;
}

SCSS

$realm-of-the-underworld: #124309;
$realm-of-the-underworld-rgb: 18, 67, 9;
$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);
}