#5C7323

CSS

:root {
  --muddy-green: #5c7323;
  --muddy-green-rgb: 92 115 35;
  --muddy-green-oklch: oklch(0.52 0.109 124);
}

.element {
  color: var(--muddy-green);
  background-color: hsl(77 53% 29%);
  border-color: oklch(0.52 0.109 124);
}

Tailwind CSS v4

@theme {
  --color-muddy-green: #5c7323;
  --color-muddy-green-50: #edfbda;
  --color-muddy-green-100: #dfefc8;
  --color-muddy-green-200: #c9ddab;
  --color-muddy-green-300: #a9c284;
  --color-muddy-green-400: #91a95f;
  --color-muddy-green-500: #779239;
  --color-muddy-green-600: #657b32;
  --color-muddy-green-700: #516328;
  --color-muddy-green-800: #3c4819;
  --color-muddy-green-900: #293210;
  --color-muddy-green-950: #171e04;
}

SCSS

$muddy-green: #5c7323;
$muddy-green-rgb: 92, 115, 35;
$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);
}