#78781B

CSS

:root {
  --olive: #78781b;
  --olive-rgb: 120 120 27;
  --olive-oklch: oklch(0.555 0.11 109.5);
}

.element {
  color: var(--olive);
  background-color: hsl(60 63% 29%);
  border-color: oklch(0.555 0.11 109.5);
}

Tailwind CSS v4

@theme {
  --color-olive: #78781b;
  --color-olive-50: #f6f9d5;
  --color-olive-100: #e8ecc2;
  --color-olive-200: #d5d9a3;
  --color-olive-300: #b9bd7a;
  --color-olive-400: #a3a452;
  --color-olive-500: #8c8c24;
  --color-olive-600: #767621;
  --color-olive-700: #5e5f1b;
  --color-olive-800: #474510;
  --color-olive-900: #31300a;
  --color-olive-950: #1d1c00;
}

SCSS

$olive: #78781b;
$olive-rgb: 120, 120, 27;
$olive-light: mix(#fff, $olive, 20%);
$olive-dark: mix(#000, $olive, 20%);

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