#5C7431

CSS

:root {
  --muddy-green: #5c7431;
  --muddy-green-rgb: 92 116 49;
  --muddy-green-oklch: oklch(0.524 0.098 126);
}

.element {
  color: var(--muddy-green);
  background-color: hsl(81 41% 32%);
  border-color: oklch(0.524 0.098 126);
}

Tailwind CSS v4

@theme {
  --color-muddy-green: #5c7431;
  --color-muddy-green-50: #edfbdd;
  --color-muddy-green-100: #deefcc;
  --color-muddy-green-200: #c8ddb0;
  --color-muddy-green-300: #a9c18c;
  --color-muddy-green-400: #90a969;
  --color-muddy-green-500: #769246;
  --color-muddy-green-600: #647b3c;
  --color-muddy-green-700: #506330;
  --color-muddy-green-800: #3b4820;
  --color-muddy-green-900: #293215;
  --color-muddy-green-950: #171e07;
}

SCSS

$muddy-green: #5c7431;
$muddy-green-rgb: 92, 116, 49;
$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);
}