PROBLEM:
The menu ribbon doesn't display properly, shadows look incorrect, things are coloured when they are not supposed to be.
Or any other unexplained visibility problems.
CAUSES:
Every graphics card, and every version of each graphics card drivers are different. Any number of things could be causing problems.
AutoDesk do not test every graphics card or drivers, and graphic card manufacturers do not test their products with Revit.
SOLUTIONS:
AutoDesk do test some graphics cards, but only high end (read expensive) 'CAD' cards. They maintain a web page with results. This tends to change, last one (14 April 2015) was at: Find Recommended Hardware
Check if your graphics card and driver are listed. Download lasted tested driver if it is listed.
If you have recently updated your graphics card wind it back to the previous driver.
Download later (or earlier) drivers for your graphics card and try them out.