Just put the disc in your PS3 (you need to set up a virtual memory card before playing).
Well, that's definitive.
It's a content thing: they have to go through all the wings and test the painting to make sure you can't paint the wrong bits, to check if the bits that should be painted somehow aren't and that there aren't any weird UV / vertex issues that affect the shading of the paint (that wouldn't necessarily show up with a traditional texture).
That would all imply that (some / most of) the wings were made before it was decided to allow us to paint them, and that's certainly true of the Standards. Hence why the newest wings, that use a parametrically morphed set of only a few models, are the only ones that can be painted, for now.