Yep, the materials room is where you do that in P5. And you can get free material packs at RDNA containing lots of sci-fi type textures, latex, rubber, metal, etc. There's also something called Dragonscales for Vicky, Mike, & probably David too, which can be applied as a Mat pose. It comes in different colors and one click re-textures the entire body -- you'll have to do the head separately -- also free from RDNA.