you guys might not be aware of this but there is a tradeoff between terrain brightness and contrast and the level of eyestrain it gives off.
thats my theory on why ah2 terrain is so dark but I think at this point the ambient lighting is fine and it is the actual texture colors that could be altered more colorfully and brighter.
currently it is very eyestrain conservative lighting and contrast.
id never thought about this till i played for a while on ozkansas map, I made the clipboard to bright and the thing is so bright compared to everything else in the screen and terrain that its painful to look at. hopefully htc will update it for next time its up with the patch i sent in that fixes that.