#807900

CSS

:root {
  --olive: #807900;
  --olive-rgb: 128 121 0;
  --olive-oklch: oklch(0.564 0.12 105.6);
}

.element {
  color: var(--olive);
  background-color: hsl(57 100% 25%);
  border-color: oklch(0.564 0.12 105.6);
}

Tailwind CSS v4

@theme {
  --color-olive: #807900;
  --color-olive-50: #f8f8d1;
  --color-olive-100: #ebebbd;
  --color-olive-200: #d9d99d;
  --color-olive-300: #bdbc72;
  --color-olive-400: #a8a247;
  --color-olive-500: #928a00;
  --color-olive-600: #7b750a;
  --color-olive-700: #635d0a;
  --color-olive-800: #4a4403;
  --color-olive-900: #332f03;
  --color-olive-950: #1f1b00;
}

SCSS

$olive: #807900;
$olive-rgb: 128, 121, 0;
$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);
}