*controlling root-level MC with internal MC*

I’ve reworking a client’s site, so I’m somewhat limited on the changes I can make to the overall structure -

BUT - here’s my quandry: I have a nav system that is on the _root level - the main content of the site exists in one large MC that sits underneath the nav, and moves to different target positions when the nav is clicked (within THIS mc are individual MC’s that house the content for each individual page)

So the nav doesn’t change positions on the timeline at all - once it loads in, it stays constant on one frame, while the main_mc moves positions underneath

I need to make the nav change color when that page is activated (when the main_mc moves into certain target positions), and I can’t figure out how to communicate w/ it from within these embedded mc’s - my AS is pretty basic, and I think this is a bit more complex then I know -

Any help is greatly appreciated - I can post the FLA file or a link ****if that helps