#816A1F

CSS

:root {
  --muddy-brown: #816a1f;
  --muddy-brown-rgb: 129 106 31;
  --muddy-brown-oklch: oklch(0.533 0.096 91.3);
}

.element {
  color: var(--muddy-brown);
  background-color: hsl(46 61% 31%);
  border-color: oklch(0.533 0.096 91.3);
}

Tailwind CSS v4

@theme {
  --color-muddy-brown: #816a1f;
  --color-muddy-brown-50: #fef5d7;
  --color-muddy-brown-100: #f2e8c4;
  --color-muddy-brown-200: #e2d4a6;
  --color-muddy-brown-300: #c8b77f;
  --color-muddy-brown-400: #b39d5a;
  --color-muddy-brown-500: #9e8331;
  --color-muddy-brown-600: #856f2b;
  --color-muddy-brown-700: #6b5922;
  --color-muddy-brown-800: #504117;
  --color-muddy-brown-900: #372c0e;
  --color-muddy-brown-950: #221902;
}

SCSS

$muddy-brown: #816a1f;
$muddy-brown-rgb: 129, 106, 31;
$muddy-brown-light: mix(#fff, $muddy-brown, 20%);
$muddy-brown-dark: mix(#000, $muddy-brown, 20%);

.element {
  color: $muddy-brown;
  box-shadow: 0 0 0 2px rgba($muddy-brown, 0.35);
}