The pickguard material that I have is black.  It doesn't thrill me much, but it's certainly better than white on this guitar.  I have to look in my pile of assorted wood that I have to see if I have any really nice thin hardwood plywood.  That might be an interesting way to go with a pickup cover.  I would use the same material for the cover plate for the volume and tone controls.  I had wanted to use a dual pot with coaxial controls, but I only found one pot like that, and it's a big one, so I'm going to use 2 mini control pots instead.  I don't have to make the hole in the body as deep for the mini pots.