#637232

CSS

:root {
  --muddy-green: #637232;
  --muddy-green-rgb: 99 114 50;
  --muddy-green-oklch: oklch(0.525 0.091 120.6);
}

.element {
  color: var(--muddy-green);
  background-color: hsl(74 39% 32%);
  border-color: oklch(0.525 0.091 120.6);
}

Tailwind CSS v4

@theme {
  --color-muddy-green: #637232;
  --color-muddy-green-50: #f0fade;
  --color-muddy-green-100: #e2edcc;
  --color-muddy-green-200: #cddbb1;
  --color-muddy-green-300: #afbf8c;
  --color-muddy-green-400: #97a769;
  --color-muddy-green-500: #7e8f47;
  --color-muddy-green-600: #6a793d;
  --color-muddy-green-700: #556130;
  --color-muddy-green-800: #3f4721;
  --color-muddy-green-900: #2b3116;
  --color-muddy-green-950: #191d07;
}

SCSS

$muddy-green: #637232;
$muddy-green-rgb: 99, 114, 50;
$muddy-green-light: mix(#fff, $muddy-green, 20%);
$muddy-green-dark: mix(#000, $muddy-green, 20%);

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