Clerk's React library offers customizable components such as <SignUp/>, <SignIn/>, and <UserProfile/>, which are styled and fully-featured to help developers focus on building their applications. The company is transitioning from a "unicorn" strategy, which required developers to use Clerk's specific theming system, to a more flexible "chameleon" strategy that allows integration with various existing styling systems. This new approach enables developers to customize components using popular styling libraries like Tailwind, CSS modules, styled-components, and Chakra, by providing a theme prop that either replaces default classes, renders custom React components, or modifies styles directly. Clerk aims to ensure compatibility with diverse styling libraries by leveraging HTML and React primitives, thereby enhancing the developer experience and addressing challenges with whitelabeling software.