You can get unfinished wood switchplates from Arnev.com (just specify you want unfinished). We got cherry ones for our kitchen, and had our cab manufacturer stain them to match our cabs.

Most of the hardware stores have wood covers. I have them throughout the house. They are a nice trim, not flat. Check prices, the same cover can run from 5 to 10. I bought mine new at Restore for 2 a piece, even with 4 openings. Run a google search for them, there are tons of offerings.

The big box stores also sell slightly textured metal ones that paint up well.

Just remember that the electrical plugs will be different color/material if you make that change
You might not care for that look

Luckily most of my electrical ones are covered by furniture. But I didn't even think about that, thanks! I'm going to run to a couple of stores today based on everyone's suggestion thank you!
Also any suggestion on the vents?? Wood ones that I can paint to match trim work?

Are your vent covers on ceilings, at top of walls, in the floor?
People depending on their HVAC system and geo location have them in various spots
in my area they are in ceilings and we usually use metal ones painted same color as the ceiling paint...

And the way I know about the switch plate covers and electrical plugs is from my own mistake...
I had granite installed in kitchen in house we own but don't live in--prepping for sale--and used the faux stone covers in kitchen backsplash...
the plugs just don't work with that look really...but I left them...
also had problem in vacation house in FL where we were having some rewiring done and adding new electrical runs..
the electricians told me that to do what I originally asked for would mean having two different plugs/switch covers in same room...
so I chose to go with the older color so I didn't have to switch out (pun intended) twice as many plugs/covers...

If you are in older house the plugs/covers are probably that ugly tan shade and the new tone going in--at least in my area--is the lighter, just not quite white tone...
I chose paint color for our new house that pretty much matches that color w/o realizing it until it was on the walls...now my wall plugs really blend into the walls...

My vents are on lower part of the wall. And the plugs a switches are white. Not sure if I find covers to paint if it would bother me with the paint being a linen white benjamin Moore and the plug and switches being the standard white. Not sure how noticeable it will be?

They also make switch plate covers that are designed for use with wall paper where you slip the paper inside to match the wall and they show through the clear plastic on the outside for easy cleaning.

You can paint your wall color on a piece of paper and slip that inside instead. Or if your switch plate is on granite or tile, you can take a picture of that tile or granite and print it out and then slip it inside the switch plate cover for a nice match.

Here is a link that might be useful: clear plastic switch plate covers

Switch plates, wall plugs, hot and cold air vents and downspouts are not design elements....best to paint them to blend in, not stand out!
I cover the switch plate covers with wall paper where I have papered and with paint where I have painted. I paint the receptical and the toggles as well. They pretty well disappear.
One of the most distracting things I see is a grill or switch plate cover that is white on a lovely warm red wall!

Is your vent made of metal? When we painted we just painted the vent also.

You can buy the cheapie switchplates, then spray them with a primer you get at walmart, and paint them the same as your walls. Easy!

I like to see the switch plates, so that it's clear where the switches are, and then to camouflage the plugs with paint or matching wallpaper. I also paint the plug receptacles themselves, against the wise advice of many. I do it anyway.

For switch plates, like Annie, I like those clear plastic ones that can be filled with anything. I've put all sorts of things in them, depending on what room they're in...New Yorker cartoons, scraps of fabric or wall paper, post cards from the museum, bits of antique maps or manuscripts, last year's Christmas cards, magazine ads for Oriental rugs, photographs, any old image at all...

If I do want them matching the wall, I just paint the inside of a plastic one, which makes them easy to wipe clean, and the shine sets the spot apart just enough so you can see them easily.

We used stone and wood wallplates in our kitchen to match the surfaces they were on.

The wood ones are cherry finished to match the natural cherry cabinets they are mounted on. They came from Arnev.com. We looked at the local hardware stores, but they only had a couple of wood species and usually only one or two configurations in a plate material like single and perhaps double. Arnev.com has plates in about any wood and configuration one would want. They have paintable primed metal plates, glass plates and many other materials too.

Our screwless stone wall plates were custom made from our backsplash stone by Columbia Gorge Stoneworks (stonewallplates.com). They can also make them from ceramic tiles. It's and expensive choice, but for this very visible surface with lots of switches and outlets, it was worth it to us.

We used Lutron matte black outlets and switches which work well with the wood and stone wallplates.

Our vents are in the floor. Most of the house has plain painted metal, but when we put hardwood in the family room/kitchen, we asked for wood ones to match the floors. They are flush to the floor.

Here is a link that might be useful: Columbia Gorge Stoneworks

LOVE the clear covers. I don't have any wallpaper but I can paint the paper the color of my walls. Great find, Annie.

Cloud swift, I love that you made the investment to keep everything in your project at the same high level of quality. It's a luxury we don't all have, but it's great to see such a good example of the result.

The devil really is in the details!