Customize UI of 6/7 Media Component - possible?

Hi - I know that Flash 8 ushered in the FLV component, with easily-skinnable bits and pieces. Is it possible to get into the earlier 6/7 Media Component and customize the UI - specifically to my project, the background color? I’m having a ***** of a time finding documentation on this subject online, which ordinarily would lead me to believe that it is NOT possible…but I’m staring at an old project file from 6 months ago wherein this very thing is happening. The guy who put this together is a) a badass, and b) unreachable.
Any ideas? Thanks in advance…