#1C4817

CSS

:root {
  --realm-of-the-underworld: #1c4817;
  --realm-of-the-underworld-rgb: 28 72 23;
  --realm-of-the-underworld-oklch: oklch(0.358 0.092 141.7);
}

.element {
  color: var(--realm-of-the-underworld);
  background-color: hsl(114 52% 19%);
  border-color: oklch(0.358 0.092 141.7);
}

Tailwind CSS v4

@theme {
  --color-realm-of-the-underworld: #1c4817;
  --color-realm-of-the-underworld-50: #e6fde5;
  --color-realm-of-the-underworld-100: #d6f0d5;
  --color-realm-of-the-underworld-200: #bedfbc;
  --color-realm-of-the-underworld-300: #9cc49a;
  --color-realm-of-the-underworld-400: #80ac7a;
  --color-realm-of-the-underworld-500: #62955c;
  --color-realm-of-the-underworld-600: #547e4e;
  --color-realm-of-the-underworld-700: #43653e;
  --color-realm-of-the-underworld-800: #314a2b;
  --color-realm-of-the-underworld-900: #21331d;
  --color-realm-of-the-underworld-950: #111f0d;
}

SCSS

$realm-of-the-underworld: #1c4817;
$realm-of-the-underworld-rgb: 28, 72, 23;
$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);
}