#7B7819

CSS

:root {
  --olive: #7b7819;
  --olive-rgb: 123 120 25;
  --olive-oklch: oklch(0.558 0.111 107.6);
}

.element {
  color: var(--olive);
  background-color: hsl(58 66% 29%);
  border-color: oklch(0.558 0.111 107.6);
}

Tailwind CSS v4

@theme {
  --color-olive: #7b7819;
  --color-olive-50: #f7f9d4;
  --color-olive-100: #eaecc1;
  --color-olive-200: #d7d9a2;
  --color-olive-300: #bbbd79;
  --color-olive-400: #a5a351;
  --color-olive-500: #8e8b21;
  --color-olive-600: #78761f;
  --color-olive-700: #605e19;
  --color-olive-800: #48440e;
  --color-olive-900: #322f09;
  --color-olive-950: #1e1c00;
}

SCSS

$olive: #7b7819;
$olive-rgb: 123, 120, 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);
}