#647236

CSS

:root {
  --muddy-green: #647236;
  --muddy-green-rgb: 100 114 54;
  --muddy-green-oklch: oklch(0.526 0.086 120.3);
}

.element {
  color: var(--muddy-green);
  background-color: hsl(74 36% 33%);
  border-color: oklch(0.526 0.086 120.3);
}

Tailwind CSS v4

@theme {
  --color-muddy-green: #647236;
  --color-muddy-green-50: #f1fadf;
  --color-muddy-green-100: #e3edce;
  --color-muddy-green-200: #cddbb2;
  --color-muddy-green-300: #afbf8e;
  --color-muddy-green-400: #97a66c;
  --color-muddy-green-500: #7e8f4b;
  --color-muddy-green-600: #6b7940;
  --color-muddy-green-700: #566133;
  --color-muddy-green-800: #3f4623;
  --color-muddy-green-900: #2c3117;
  --color-muddy-green-950: #191d08;
}

SCSS

$muddy-green: #647236;
$muddy-green-rgb: 100, 114, 54;
$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);
}