Google's Messages app has introduced new chat themes that allow users to change conversation backgrounds by selecting from various photos or uploading their own images. This feature personalizes the chat experience and adjusts chat bubble colors to match the background. Currently, themes are only visible to the user who applies them, limiting shared experiences. Users have suggested improvements, such as on-device background generation and syncing themes across devices. Additionally, some users have reported a bug where the app may freeze when tapping on a theme without applying it, although this issue varies among users.