Stainless and paint
I did not paint the interior firewall either- primarily because it is stainless steel. Very difficult to get good adhesion to this, even with good paint (I used ANAC epoxy primer and Imron on the rest of my interior). You can barely see it anyway with the pedals installed. There is an insulating material that is meant for firewalls that could be installed instead but there is very little clearance between the pedals and the firewall when the pedals are fully depressed.
You had asked about painting the pedals- why would you want to do this? Just a different color?? They are powdercoated and I would think it would be difficult to get paint to adhere well to a powdercoating but I am far from a paint expert.
Jeff