The model railroad guys seem to use tons of this stuff , and most of the data I've seen from them would indicate that blue foam is the prefered foam followed by the pink. (I've seen blue, pink, tan and white - think the color indicates density, with blue being the highest). The Home Depot I was in last week had blue, pink and white in 1/2", 1" and 2" thicknesses in stock. Be prepared though, it's really messy to carve and shave (unless you buy one of the electric carving tools - and if you do, use a good respirator when using the tool). And you'll learn to hate static electricity.