#876811

CSS

:root {
  --muddy-brown: #876811;
  --muddy-brown-rgb: 135 104 17;
  --muddy-brown-oklch: oklch(0.534 0.104 86.7);
}

.element {
  color: var(--muddy-brown);
  background-color: hsl(44 78% 30%);
  border-color: oklch(0.534 0.104 86.7);
}

Tailwind CSS v4

@theme {
  --color-muddy-brown: #876811;
  --color-muddy-brown-50: #fff4d4;
  --color-muddy-brown-100: #f6e7c1;
  --color-muddy-brown-200: #e6d3a2;
  --color-muddy-brown-300: #cdb579;
  --color-muddy-brown-400: #b99a52;
  --color-muddy-brown-500: #a48124;
  --color-muddy-brown-600: #8b6d21;
  --color-muddy-brown-700: #6f571a;
  --color-muddy-brown-800: #533f11;
  --color-muddy-brown-900: #3a2b0a;
  --color-muddy-brown-950: #241901;
}

SCSS

$muddy-brown: #876811;
$muddy-brown-rgb: 135, 104, 17;
$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);
}