#5B7525

CSS

:root {
  --muddy-green: #5b7525;
  --muddy-green-rgb: 91 117 37;
  --muddy-green-oklch: oklch(0.525 0.111 125.5);
}

.element {
  color: var(--muddy-green);
  background-color: hsl(80 52% 30%);
  border-color: oklch(0.525 0.111 125.5);
}

Tailwind CSS v4

@theme {
  --color-muddy-green: #5b7525;
  --color-muddy-green-50: #ecfcda;
  --color-muddy-green-100: #deefc8;
  --color-muddy-green-200: #c7deab;
  --color-muddy-green-300: #a8c285;
  --color-muddy-green-400: #8faa60;
  --color-muddy-green-500: #75933a;
  --color-muddy-green-600: #637c32;
  --color-muddy-green-700: #4f6328;
  --color-muddy-green-800: #3b491a;
  --color-muddy-green-900: #283211;
  --color-muddy-green-950: #161e04;
}

SCSS

$muddy-green: #5b7525;
$muddy-green-rgb: 91, 117, 37;
$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);
}