Are you talking about the silver parts or the dark gray parts underneath? I would highly recommend against painting the dark gray parts because most of them see wear and tear from the seat rubbing up against it when you move it front or back and even when getting into the vehicle, your knees as you are driving down the road or the seat belt as you put it on or move around in your seat. The silver part wouldn't be too hard for a professional shop to do, just a matter of not breaking anything during removal or reinstallation or when prepping for paint. One thing you will want to be especially careful of is the vents and not breaking the little tabs off when pulling them out.

Hope this helps