Some parts are coated by an electrostatic process. To get paint to adhere to old paint or powdercoat, prep will be required. If the pegs themselves are to be painted the first time a passenger rides. the paint is going to wear away on the grip surface. Best to use automotive paint. Some, like DuPont Centari do not require the use of hardners. I'd apply aboot four coats..
Rear brackets actually look pretty good black IMO. Link to this thread for a pic: First impressions on my 03 VFR It's a 6th Gen but should give you idea how things will look. As for what finish is on them from the factory, I think they're painted. I say this because the area where the bag brackets attach on mine are scratch up a little from removal/ installation. Looks to me like paint. I could be very wrong about that.