#887311

CSS

:root {
  --muddy-brown: #887311;
  --muddy-brown-rgb: 136 115 17;
  --muddy-brown-oklch: oklch(0.559 0.11 95.6);
}

.element {
  color: var(--muddy-brown);
  background-color: hsl(49 78% 30%);
  border-color: oklch(0.559 0.11 95.6);
}

Tailwind CSS v4

@theme {
  --color-muddy-brown: #887311;
  --color-muddy-brown-50: #fdf6d3;
  --color-muddy-brown-100: #f2e9bf;
  --color-muddy-brown-200: #e1d59f;
  --color-muddy-brown-300: #c6b876;
  --color-muddy-brown-400: #b29e4d;
  --color-muddy-brown-500: #9c8518;
  --color-muddy-brown-600: #847018;
  --color-muddy-brown-700: #6a5a14;
  --color-muddy-brown-800: #4f410b;
  --color-muddy-brown-900: #372d07;
  --color-muddy-brown-950: #221a00;
}

SCSS

$muddy-brown: #887311;
$muddy-brown-rgb: 136, 115, 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);
}