RanTheCid wrote:Let the color come from the terrain your putting on top of the table. Be sure that several different colors are represented. Nothing sucks more than an all gray COD table. Use some reds, browns and greens - then wash them all down with black/brown to blend together.
This. A little drybrushing to spice up a plain black board is plenty, if it's going to be covered by terrain. If your city won't be particularly dense, I'd add a few permanently modeled features to the boards - nothing too huge, since it would disrupt your ability to lay down scatter terrain, but something you can paint up with a few more colors to break up the monotony (e.g. brown dirt scattered around a blast crater that broke through the asphalt), but can be blended back into the general color to avoid looking jarringly out of place.
Roads are an often neglected part of urban boards, it seems, but are worth a second mention, I think. A quick trip to Home Depot will net you a pack of asphalt-colored roofing shingles which can easily be cut into road segments. Laying a few of those down might help break up lines and cover seams, without dictating the lay of your modular boards. A little masking and some paint to give them lines will keep them distinct from your vaguely asphalt-like base board, even without distinct curbs.