#623200

CSS

:root {
  --brown: #623200;
  --brown-rgb: 98 50 0;
  --brown-oklch: oklch(0.372 0.089 58.2);
}

.element {
  color: var(--brown);
  background-color: hsl(31 100% 19%);
  border-color: oklch(0.372 0.089 58.2);
}

Tailwind CSS v4

@theme {
  --color-brown: #623200;
  --color-brown-50: #fff0dc;
  --color-brown-100: #ffe2cb;
  --color-brown-200: #f1ccaf;
  --color-brown-300: #daad8a;
  --color-brown-400: #c69169;
  --color-brown-500: #b27747;
  --color-brown-600: #96653d;
  --color-brown-700: #795031;
  --color-brown-800: #5a3a23;
  --color-brown-900: #3f2817;
  --color-brown-950: #281608;
}

SCSS

$brown: #623200;
$brown-rgb: 98, 50, 0;
$brown-light: mix(#fff, $brown, 20%);
$brown-dark: mix(#000, $brown, 20%);

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