#637413

CSS

:root {
  --topiary-green: #637413;
  --topiary-green-rgb: 99 116 19;
  --topiary-green-oklch: oklch(0.527 0.117 119.7);
}

.element {
  color: var(--topiary-green);
  background-color: hsl(71 72% 26%);
  border-color: oklch(0.527 0.117 119.7);
}

Tailwind CSS v4

@theme {
  --color-topiary-green: #637413;
  --color-topiary-green-50: #effbd6;
  --color-topiary-green-100: #e1efc3;
  --color-topiary-green-200: #ccdda5;
  --color-topiary-green-300: #adc17d;
  --color-topiary-green-400: #96a855;
  --color-topiary-green-500: #7d9129;
  --color-topiary-green-600: #6a7b25;
  --color-topiary-green-700: #55621d;
  --color-topiary-green-800: #3f4711;
  --color-topiary-green-900: #2b320b;
  --color-topiary-green-950: #191d01;
}

SCSS

$topiary-green: #637413;
$topiary-green-rgb: 99, 116, 19;
$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);
}