#7D771F

CSS

:root {
  --olive: #7d771f;
  --olive-rgb: 125 119 31;
  --olive-oklch: oklch(0.558 0.106 105.4);
}

.element {
  color: var(--olive);
  background-color: hsl(56 60% 31%);
  border-color: oklch(0.558 0.106 105.4);
}

Tailwind CSS v4

@theme {
  --color-olive: #7d771f;
  --color-olive-50: #f8f8d5;
  --color-olive-100: #ebebc3;
  --color-olive-200: #d8d8a4;
  --color-olive-300: #bdbc7b;
  --color-olive-400: #a7a254;
  --color-olive-500: #908a27;
  --color-olive-600: #7a7524;
  --color-olive-700: #625d1c;
  --color-olive-800: #494411;
  --color-olive-900: #332f0b;
  --color-olive-950: #1e1b01;
}

SCSS

$olive: #7d771f;
$olive-rgb: 125, 119, 31;
$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);
}