I'm using FileMaker Pro Advanced 12.0v4 on an iMac running OS X 10.8.4.
Here is my data-entry screen in Layout Mode. Notice that I'm using a gradient background for the header part, and a light-gray background for the "housekeepeing" fields at the lower left:
Here is the same screen in Browse mode. Notice that, while the active record has the desired light-gray background, the inactive one does not:
Here is the same screen in Preview mode. Notice that the light-gray background has vanished from the fields, and the gradient background has vanished from the header part and the 2 banner fields within it. (The buttons are set to non-printing, and the title info and logo are set to slide left, so that behavior was expected.)
Where are my background colors?