#787919

CSS

:root {
  --olive: #787919;
  --olive-rgb: 120 121 25;
  --olive-oklch: oklch(0.558 0.113 110.2);
}

.element {
  color: var(--olive);
  background-color: hsl(61 66% 29%);
  border-color: oklch(0.558 0.113 110.2);
}

Tailwind CSS v4

@theme {
  --color-olive: #787919;
  --color-olive-50: #f5f9d4;
  --color-olive-100: #e8ecc1;
  --color-olive-200: #d5daa2;
  --color-olive-300: #b8be79;
  --color-olive-400: #a2a451;
  --color-olive-500: #8b8c21;
  --color-olive-600: #75771f;
  --color-olive-700: #5e5f19;
  --color-olive-800: #46450e;
  --color-olive-900: #313009;
  --color-olive-950: #1d1c00;
}

SCSS

$olive: #787919;
$olive-rgb: 120, 121, 25;
$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);
}