I've been using Createx paint on my foam airplanes and wanted to let everyone know that it works great and does not damage foam. The paint is water-based, designed to be airbrushed and will stick on just about anything. It comes in 76 different colors including opaques, transparent, pearl, iridescent, fluorescent and chameleon (changes color depending on what angle it's viewed at). The opaques and fluorescent colors can be brushed on, but airbrushing is much better. You can get a retarder which will slow down the drying time in hot and/or humid areas, a clear-coat (most of the colors dry with a flat finish) and a flexirizer (makes the paint flexible so it won't crack and peel when sprayed onto something...well, flexible). By the way; for those of you who also run R/C cars, this is the same
paint that Parma International sells under the Faskolor name to paint clear Lexan bodies - except it's cheaper to buy it under it's original name plus it is available in larger bottles. Createx is available at many artist and crafts stores.