#876718

CSS

:root {
  --muddy-brown: #876718;
  --muddy-brown-rgb: 135 103 24;
  --muddy-brown-oklch: oklch(0.532 0.1 84.8);
}

.element {
  color: var(--muddy-brown);
  background-color: hsl(43 70% 31%);
  border-color: oklch(0.532 0.1 84.8);
}

Tailwind CSS v4

@theme {
  --color-muddy-brown: #876718;
  --color-muddy-brown-50: #fff4d5;
  --color-muddy-brown-100: #f6e6c3;
  --color-muddy-brown-200: #e7d2a4;
  --color-muddy-brown-300: #ceb57b;
  --color-muddy-brown-400: #ba9a56;
  --color-muddy-brown-500: #a5802b;
  --color-muddy-brown-600: #8b6d26;
  --color-muddy-brown-700: #6f571e;
  --color-muddy-brown-800: #533f14;
  --color-muddy-brown-900: #3a2b0d;
  --color-muddy-brown-950: #241802;
}

SCSS

$muddy-brown: #876718;
$muddy-brown-rgb: 135, 103, 24;
$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);
}