#517700

CSS

:root {
  --over-the-hills: #517700;
  --over-the-hills-rgb: 81 119 0;
  --over-the-hills-oklch: oklch(0.521 0.137 128.4);
}

.element {
  color: var(--over-the-hills);
  background-color: hsl(79 100% 23%);
  border-color: oklch(0.521 0.137 128.4);
}

Tailwind CSS v4

@theme {
  --color-over-the-hills: #517700;
  --color-over-the-hills-50: #e8fed5;
  --color-over-the-hills-100: #d9f2c2;
  --color-over-the-hills-200: #c1e1a3;
  --color-over-the-hills-300: #a0c67a;
  --color-over-the-hills-400: #86ae50;
  --color-over-the-hills-500: #6b961f;
  --color-over-the-hills-600: #5a7f1d;
  --color-over-the-hills-700: #486618;
  --color-over-the-hills-800: #364a0b;
  --color-over-the-hills-900: #253407;
  --color-over-the-hills-950: #141f00;
}

SCSS

$over-the-hills: #517700;
$over-the-hills-rgb: 81, 119, 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);
}