#7B7721

CSS

:root {
  --olive: #7b7721;
  --olive-rgb: 123 119 33;
  --olive-oklch: oklch(0.556 0.105 106.7);
}

.element {
  color: var(--olive);
  background-color: hsl(57 58% 31%);
  border-color: oklch(0.556 0.105 106.7);
}

Tailwind CSS v4

@theme {
  --color-olive: #7b7721;
  --color-olive-50: #f7f8d6;
  --color-olive-100: #eaebc3;
  --color-olive-200: #d7d8a5;
  --color-olive-300: #bbbc7c;
  --color-olive-400: #a6a356;
  --color-olive-500: #8f8a2a;
  --color-olive-600: #797526;
  --color-olive-700: #615e1e;
  --color-olive-800: #484413;
  --color-olive-900: #322f0c;
  --color-olive-950: #1e1b01;
}

SCSS

$olive: #7b7721;
$olive-rgb: 123, 119, 33;
$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);
}