#5B722E

CSS

:root {
  --muddy-green: #5b722e;
  --muddy-green-rgb: 91 114 46;
  --muddy-green-oklch: oklch(0.518 0.098 125.3);
}

.element {
  color: var(--muddy-green);
  background-color: hsl(80 43% 31%);
  border-color: oklch(0.518 0.098 125.3);
}

Tailwind CSS v4

@theme {
  --color-muddy-green: #5b722e;
  --color-muddy-green-50: #edfbdd;
  --color-muddy-green-100: #dfefcc;
  --color-muddy-green-200: #c9ddb0;
  --color-muddy-green-300: #a9c18b;
  --color-muddy-green-400: #91a968;
  --color-muddy-green-500: #779145;
  --color-muddy-green-600: #657b3b;
  --color-muddy-green-700: #50632f;
  --color-muddy-green-800: #3c4820;
  --color-muddy-green-900: #293215;
  --color-muddy-green-950: #171e06;
}

SCSS

$muddy-green: #5b722e;
$muddy-green-rgb: 91, 114, 46;
$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);
}