Depending on how experimental you want to get with them, I'd say look into vinyl dye. I've used it several times in the past on marine grade vinyl material and it worked great. Comes in a rattle can and you can get it at any autoparts store or wal-mart. Sprays on like paint, but saturates the material much more.
Throw the photoshoppers a bone and post your executed mods, we would like to see the after pics. Copy and paste the url. http://www.jeepforum.com/forum/f59/executed-photoshop-mods-1417032/