iA Presenter is my favorite software for writing and presenting a story. Presenter comes with a set of themes to provide a suitable visual style for your message. You can add your own custom themes to even fit the tool better to your needs. That´s what I did with Plex: It is a custom iA Presenter theme based on the IBM Plex typeface with vibrant dynamic background colors.
See it here: Plex in action!
Download Plex at github.com/ulfschneider/Plex.