If you need to emphasize a menu item (call to action, donate button, etc..) just go to your WordPress Dashboard under “Appearance-> Menus”. Create a new “Custom Links” and drag it into the menu. Expand the entry and in the “CSS Classes” section write: crestaMenuButton
This will be the result (the colors change according to the ones chosen).
NB: if you don’t see the “CSS Classes” field on your screen, just click on the “Screen Options” button at the top-right of the page, and check the option called “CSS Classes“