#AD611A

CSS

:root {
  --light-brown: #ad611a;
  --light-brown-rgb: 173 97 26;
  --light-brown-oklch: oklch(0.569 0.126 57.6);
}

.element {
  color: var(--light-brown);
  background-color: hsl(29 74% 39%);
  border-color: oklch(0.569 0.126 57.6);
}

Tailwind CSS v4

@theme {
  --color-light-brown: #ad611a;
  --color-light-brown-50: #ffedd2;
  --color-light-brown-100: #ffdfbe;
  --color-light-brown-200: #fdc89e;
  --color-light-brown-300: #e7a874;
  --color-light-brown-400: #d68a4e;
  --color-light-brown-500: #c36d1c;
  --color-light-brown-600: #a45d1b;
  --color-light-brown-700: #844a16;
  --color-light-brown-800: #63350f;
  --color-light-brown-900: #452409;
  --color-light-brown-950: #2d1300;
}

SCSS

$light-brown: #ad611a;
$light-brown-rgb: 173, 97, 26;
$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);
}