We do it all the time. The only hitch is that the plates themselves may be more durable with the factory finish than if you were to paint them with wall paint, so they may not hold up as well. We also don't paint the plugs themselves or the switches themselves.

I paint switch and cover plates all the time ... but not while they are on. If you paint them mounted they will be brushed or rolled oddly compared to your nice vertical wall. Personally, I like them to stick out so visitors can see where the switches are.

If my trim is a standard color (white/ivory) ... I replace the actual switch or outlet to match. Tricky but not hard to do -- turn the circuit breaker off! An electrician will swap these out for $10/each if you like. The new cover plates you can buy new for $2 or up depending on if you want plastic or whatever.

If your trim is a UNIQUE color (or your wall is a unique color) ... you can paint both the outlets or switches and their covers! I do this also when the old covers are nice metal with a textured pattern. Remove them, sand them a bit, prime and 2 coats. Plugs and switches are a pain in the rear to paint but some (in my house are adhered to their location) -- clean them with a cue-tip and windex -- don't let it drip in the socket! Prime and paint with a tiny brush or tape off and spray. Just takes patience but they can look fabulous.

I read some threads where people were raving about their painted wall plates. I mentioned this to my painter and he looked at me like I was out of my mind.

Oh totally. I have all the warts painted including vents - always. I don't do the switches or plugs, however. You probably can't find many pictures because everyone Photoshops them out so their "after" shots are Pinterest worthy.

I run them through the dishwasher first. Never sanded or primed. Just two coats and never use cheap paint. When they get gross looking, like bathroom/kitchen switch plates always get hit hard, I just run them through the dishwasher again. Usually with a few ball caps so I don't waste water running a load.

If they don't make through the second wash painted, I go buy new ones and repeat the process with my stash of left-over touch-up paint. Trick is to use a standard, plain, easy-to-replace design in the first place.

Hmmm. Maybe you can tell I have boys and dogs and the dishwasher is one of my best friends. :)

I routinely painted switch and outlet plates to match the walls, but they were always removed and painted separately. The outlets themselves were taped over during painting of the wall. I dislike routinely painting air vents and returns, at least with conventional wall paint. The factory finish enamel is much easier to clean and its slick surface does not grab dirt out of the air passing through it.

The older type crinkled metal plates hold paint better, but plastic plates can also be painted if scuffed up first with fine sandpaper.