#81781A

CSS

:root {
  --olive: #81781a;
  --olive-rgb: 129 120 26;
  --olive-oklch: oklch(0.564 0.11 103.6);
}

.element {
  color: var(--olive);
  background-color: hsl(55 66% 30%);
  border-color: oklch(0.564 0.11 103.6);
}

Tailwind CSS v4

@theme {
  --color-olive: #81781a;
  --color-olive-50: #f9f8d4;
  --color-olive-100: #ecebc1;
  --color-olive-200: #dad8a1;
  --color-olive-300: #bfbb78;
  --color-olive-400: #aaa150;
  --color-olive-500: #93891f;
  --color-olive-600: #7c741d;
  --color-olive-700: #635d18;
  --color-olive-800: #4a430e;
  --color-olive-900: #342e08;
  --color-olive-950: #1f1b00;
}

SCSS

$olive: #81781a;
$olive-rgb: 129, 120, 26;
$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);
}