I updated my game--I now have the highlighted 3 fruits like you mentioned, VGailP. All it is is a suggested move/match--I was wondering why they didn't have it in this game (it's common to the other "Mania's" I've played.) I notice it only shows 3 fruit, even when there are lots of same-color fruit together.
Don't know if I still have shading, though. There's not much blaster action on my current level. If not, I'd better quit talking about it--confusing people! Anyway, mystery solved, lol!
Edit: Yes, there's still shading. Just press on a blaster...you'll see the row or column it's in become grayed-out. 'Course, it won't detonate, since it must be in a 3 or more fruit chain to be activated. And one last time--where that chain
ends, is where the blaster blasts!