ActionScript 3.0 :: Creating A Color Changing, Number-based Navigation Menu?

In a nutshell, the swf contains four ads (which link to portions of the site) and each ad uses the Timer element, displaying it for 5 seconds before moving on to the next one. Everything has come together nicely (although I'd like to clean up the code and use classes at a later date - I'm currently taking AS training from Lynda.com).
 
What's giving me trouble right now is the navigation bar. What I want to do is create four numerical buttons that a) change color during a mouse roll over b) change color for a corresponding ad (for example, when the third ad displays, the number "3" changes from white to gray to show that it is active and goes back to white when the fourth ad comes up).
 
Right now, I'm at a loss as to what to do. I've tried making the numbers buttons, but I can't control color changes unless I create two sets of buttons: one with white numbers, one with gray numbers.This also makes for some really bizarre Actionscript coding ideas (ex: after I code the function for the gray nav buttons, I have to code functions that make the white buttons work - but this ends up screwing with the ad cycles). I tried making them as movie clips, but I lose the ability to assign a large hit area like I can with buttons.