These are the example files for FileMaker 12 in Depth. They use a variety of themes to show you what you have to work with. In most cases, for a single FileMaker solution you do not use a different theme for each layout because it can distract the user. Here, however, the goal is to distract you and show you the themes.
Note that in Chapters 9 and 13, you have examples based on the Starter Solutions from pre-FileMaker 12 versions. Use them to explore the Layouts menu Change Theme command in Layout mode. See what you can come up with! (And remember to save the files before experimenting, so that you can go back and change them some more.