UI theme is a set of parameters that determine how to render the elements on your page. ForeUI allows you to change the style of your prototype by simply switch UI theme.
Here is an example, the prototype below is using the "Blueprint" UI theme.
If you want a different low-fidelity style, you can try the "Hand Drawn" UI theme:
After switching the UI theme to "Wireframe", it looks like this:
If you like to have a high fidelity prototype, you can choose "Windows XP", "Windows 7", "Windows 8", "Ubuntu" or "Mac OS X" UI theme.
The UI themes are packed as a ZIP format files (with .thm file extension) and stored in the "theme" folder under the ForeUI install directory. ForeUI will have a plugin to design UI theme in the future.