#65721D

CSS

:root {
  --topiary-green: #65721d;
  --topiary-green-rgb: 101 114 29;
  --topiary-green-oklch: oklch(0.524 0.108 117.9);
}

.element {
  color: var(--topiary-green);
  background-color: hsl(69 59% 28%);
  border-color: oklch(0.524 0.108 117.9);
}

Tailwind CSS v4

@theme {
  --color-topiary-green: #65721d;
  --color-topiary-green-50: #f1fad8;
  --color-topiary-green-100: #e3eec6;
  --color-topiary-green-200: #cedca8;
  --color-topiary-green-300: #b0c081;
  --color-topiary-green-400: #99a75b;
  --color-topiary-green-500: #808f32;
  --color-topiary-green-600: #6c792c;
  --color-topiary-green-700: #576123;
  --color-topiary-green-800: #414716;
  --color-topiary-green-900: #2d310e;
  --color-topiary-green-950: #1a1d02;
}

SCSS

$topiary-green: #65721d;
$topiary-green-rgb: 101, 114, 29;
$topiary-green-light: mix(#fff, $topiary-green, 20%);
$topiary-green-dark: mix(#000, $topiary-green, 20%);

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