#AD651D

CSS

:root {
  --light-brown: #ad651d;
  --light-brown-rgb: 173 101 29;
  --light-brown-oklch: oklch(0.576 0.123 59.9);
}

.element {
  color: var(--light-brown);
  background-color: hsl(30 71% 40%);
  border-color: oklch(0.576 0.123 59.9);
}

Tailwind CSS v4

@theme {
  --color-light-brown: #ad651d;
  --color-light-brown-50: #ffeed2;
  --color-light-brown-100: #ffe0bf;
  --color-light-brown-200: #fbc99e;
  --color-light-brown-300: #e5a974;
  --color-light-brown-400: #d38c4e;
  --color-light-brown-500: #c06f1c;
  --color-light-brown-600: #a25f1b;
  --color-light-brown-700: #824c16;
  --color-light-brown-800: #61360f;
  --color-light-brown-900: #442509;
  --color-light-brown-950: #2c1300;
}

SCSS

$light-brown: #ad651d;
$light-brown-rgb: 173, 101, 29;
$light-brown-light: mix(#fff, $light-brown, 20%);
$light-brown-dark: mix(#000, $light-brown, 20%);

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