#6A3900

CSS

:root {
  --brown: #6a3900;
  --brown-rgb: 106 57 0;
  --brown-oklch: oklch(0.398 0.093 60.7);
}

.element {
  color: var(--brown);
  background-color: hsl(32 100% 21%);
  border-color: oklch(0.398 0.093 60.7);
}

Tailwind CSS v4

@theme {
  --color-brown: #6a3900;
  --color-brown-50: #fff0db;
  --color-brown-100: #ffe2c9;
  --color-brown-200: #f2ccac;
  --color-brown-300: #daad86;
  --color-brown-400: #c79265;
  --color-brown-500: #b37742;
  --color-brown-600: #976539;
  --color-brown-700: #79502d;
  --color-brown-800: #5a3a20;
  --color-brown-900: #3f2815;
  --color-brown-950: #281607;
}

SCSS

$brown: #6a3900;
$brown-rgb: 106, 57, 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);
}