#7D7719

CSS

:root {
  --olive: #7d7719;
  --olive-rgb: 125 119 25;
  --olive-oklch: oklch(0.558 0.11 105.6);
}

.element {
  color: var(--olive);
  background-color: hsl(56 67% 29%);
  border-color: oklch(0.558 0.11 105.6);
}

Tailwind CSS v4

@theme {
  --color-olive: #7d7719;
  --color-olive-50: #f8f8d4;
  --color-olive-100: #ebebc1;
  --color-olive-200: #d8d8a2;
  --color-olive-300: #bdbc79;
  --color-olive-400: #a7a251;
  --color-olive-500: #918a21;
  --color-olive-600: #7a751f;
  --color-olive-700: #625d19;
  --color-olive-800: #49440e;
  --color-olive-900: #332f09;
  --color-olive-950: #1e1b00;
}

SCSS

$olive: #7d7719;
$olive-rgb: 125, 119, 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);
}