Unfortunately there's nothing that's easily configurable through SharePoint options. If you're familiar with html and css, you can design the top nav however you'd like.
The simplest way is to add a custom css file that targets the respective elements in the top nav and alters the way they show up. There are plenty of resources around for doing this.
Another more advanced approach is to hide the top navigation control in the masterpage and build out a navigation menu from scratch. It can pull data in dynamically using SharePoint's REST api so new sites show up automatically as well.