#5E3900

CSS

:root {
  --brown: #5e3900;
  --brown-rgb: 94 57 0;
  --brown-oklch: oklch(0.38 0.083 69.6);
}

.element {
  color: var(--brown);
  background-color: hsl(36 100% 18%);
  border-color: oklch(0.38 0.083 69.6);
}

Tailwind CSS v4

@theme {
  --color-brown: #5e3900;
  --color-brown-50: #fff2dc;
  --color-brown-100: #fae4cb;
  --color-brown-200: #ebcfae;
  --color-brown-300: #d2b189;
  --color-brown-400: #be9668;
  --color-brown-500: #a97c46;
  --color-brown-600: #8f693c;
  --color-brown-700: #735430;
  --color-brown-800: #553d22;
  --color-brown-900: #3c2a16;
  --color-brown-950: #251707;
}

SCSS

$brown: #5e3900;
$brown-rgb: 94, 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);
}