A couple years ago I had an add-on that would colour unexplored areas of a zone map in pink. This made getting the exploring achievements fairly simple. I can't remember the name of the add-on now, though. Does anyone have an idea? (It isn't Cartographer.)
MozzFullWorldMap offers the ability to change the shade of unexplored map areas and works for 3.3.3. I thought Cartographer did this also, but if you're sure it's not the right one, then do some research on MozzFullWorldMap and see if it offers the feature you mean.
