#837819

CSS

:root {
  --olive: #837819;
  --olive-rgb: 131 120 25;
  --olive-oklch: oklch(0.566 0.11 102.4);
}

.element {
  color: var(--olive);
  background-color: hsl(54 68% 31%);
  border-color: oklch(0.566 0.11 102.4);
}

Tailwind CSS v4

@theme {
  --color-olive: #837819;
  --color-olive-50: #faf7d4;
  --color-olive-100: #edeac0;
  --color-olive-200: #dbd7a1;
  --color-olive-300: #c0bb77;
  --color-olive-400: #aba14f;
  --color-olive-500: #95881d;
  --color-olive-600: #7e731c;
  --color-olive-700: #655c16;
  --color-olive-800: #4b430d;
  --color-olive-900: #342e08;
  --color-olive-950: #201b00;
}

SCSS

$olive: #837819;
$olive-rgb: 131, 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);
}