Keycloak includes user interfaces (UIs) for the login page, Admin Console, and Account Console. It also has a "welcome" screen used for the first administrator of the Admin Console.
You can customize, extend, and modify these UIs to accommodate many use cases on your production systems. At a minimum, you will need to change the logos and colors to match your corporate identity. Also, you may modify the UIs to implement new functionality.
This guide provides all the information needed to customize the Keycloak UIs for your needs.