What CSS framework does Breeze auth template use?

I'm trying to make my login screen dark themed, google says that it uses tailwind but tailwind's bg color classes aren't working on the page.

For example, the main background color comes from a bg-gray-100 class in the views/components/auth-card.blade.php file by default, I'm trying to change it to a dark colored tailwind class, it turns into a bright white.

I tried almost every color on the list (2nd image) and only 2 of them are working bg-gray-100 (default one) and bg-gray-800