#6D4000

CSS

:root {
  --brown: #6d4000;
  --brown-rgb: 109 64 0;
  --brown-oklch: oklch(0.416 0.092 66.4);
}

.element {
  color: var(--brown);
  background-color: hsl(35 100% 21%);
  border-color: oklch(0.416 0.092 66.4);
}

Tailwind CSS v4

@theme {
  --color-brown: #6d4000;
  --color-brown-50: #fff1da;
  --color-brown-100: #fde3c8;
  --color-brown-200: #efceaa;
  --color-brown-300: #d7af84;
  --color-brown-400: #c49462;
  --color-brown-500: #af793e;
  --color-brown-600: #946735;
  --color-brown-700: #77522a;
  --color-brown-800: #593b1e;
  --color-brown-900: #3e2913;
  --color-brown-950: #271605;
}

SCSS

$brown: #6d4000;
$brown-rgb: 109, 64, 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);
}