I have a set of green flocked boards that I use for Northern Europe and another set of dusty grey-brown boards (my Zama boards) that I use for the south. The minis are on grey brown bases with clumps of grass and look OK with both.
re Trebian above, I was taking pics today of the Lake Trasimene area with a future game in mind. by the lake, there were many more Italian girls in bikinis than I had expected to see from accounts of the battle. ;-). Also far more trees on the hills. Unless the terrain has changed (always possible) it would have been very easy to conceal a dozen Carthaginian armies in the area, and very easy for them to approach the road under cover. There would also have been a substantial marshy shoreline with reed banks behind the Romans. A terrain-rich battlefield!