#9FA464

CSS

:root {
  --willow-leaf: #9fa464;
  --willow-leaf-rgb: 159 164 100;
  --willow-leaf-oklch: oklch(0.7 0.086 112.2);
}

.element {
  color: var(--willow-leaf);
  background-color: hsl(65 26% 52%);
  border-color: oklch(0.7 0.086 112.2);
}

Tailwind CSS v4

@theme {
  --color-willow-leaf: #9fa464;
  --color-willow-leaf-50: #f4f8dd;
  --color-willow-leaf-100: #e7eccb;
  --color-willow-leaf-200: #d3d9af;
  --color-willow-leaf-300: #b6bd8a;
  --color-willow-leaf-400: #9fa468;
  --color-willow-leaf-500: #878c45;
  --color-willow-leaf-600: #72763b;
  --color-willow-leaf-700: #5b5f2f;
  --color-willow-leaf-800: #444520;
  --color-willow-leaf-900: #2f3015;
  --color-willow-leaf-950: #1c1c07;
}

SCSS

$willow-leaf: #9fa464;
$willow-leaf-rgb: 159, 164, 100;
$willow-leaf-light: mix(#fff, $willow-leaf, 20%);
$willow-leaf-dark: mix(#000, $willow-leaf, 20%);

.element {
  color: $willow-leaf;
  box-shadow: 0 0 0 2px rgba($willow-leaf, 0.35);
}