#537200

CSS

:root {
  --over-the-hills: #537200;
  --over-the-hills-rgb: 83 114 0;
  --over-the-hills-oklch: oklch(0.509 0.13 126.1);
}

.element {
  color: var(--over-the-hills);
  background-color: hsl(76 100% 22%);
  border-color: oklch(0.509 0.13 126.1);
}

Tailwind CSS v4

@theme {
  --color-over-the-hills: #537200;
  --color-over-the-hills-50: #eafdd6;
  --color-over-the-hills-100: #dbf1c3;
  --color-over-the-hills-200: #c4dfa4;
  --color-over-the-hills-300: #a4c47c;
  --color-over-the-hills-400: #8bac53;
  --color-over-the-hills-500: #709524;
  --color-over-the-hills-600: #5f7e21;
  --color-over-the-hills-700: #4c651a;
  --color-over-the-hills-800: #39490e;
  --color-over-the-hills-900: #273309;
  --color-over-the-hills-950: #151f00;
}

SCSS

$over-the-hills: #537200;
$over-the-hills-rgb: 83, 114, 0;
$over-the-hills-light: mix(#fff, $over-the-hills, 20%);
$over-the-hills-dark: mix(#000, $over-the-hills, 20%);

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