It depends, what style are you going with your room, home. Traditional, contemporary, etc.

Here is another view of the space:

This kitchen was a major inspiration:

Craftsman Kitchen · More Info

Either works,,it depends what you want. They are different styles,so it depends what you like

Beautiful kitchen and dining nook. I think it would look nice either way. The stained shelves may hold up better in terms of scratches, scuffs, etc. Your rooms flow nicely together. Love your light fixture!

I really could go either way. We were on a budget, so couldn't go with the wood on the island and I was thinking the added wood on the shelves could give the warmth I was looking for. But, when we put the sanded down shelves in to get a feel for it, I thought it looked a bit cluttered. We're a family of six so we've got enough clutter going as it is... :) and to add in our display items (which aren't all curated cream tones) I'm starting to lean towards white shelves.
I guess I was just looking for opinions to help tip the scales one way or the other.

I love to see before and afters, so here are some "befores"

Thank you for your kind words, Karen!

Such a difference! You did a great job with this renovation.
The wood color shelves look a bit more country, which is fine if that is what you are going for.

Keep the shelves as is/ stained. I would think about adding some interest and texture w/perhaps wall papering the back of the built in (e.g. Large scale plaid or neutral damask or grass cloth?) Beautiful job!

Painting them white would appear as a whole wall. I have a white built in with white shelves, and the back wall is a dark red. Personally I like your shelves the way they are.

My vote would definitely be for staining the shelves over painting.

You are welcome, I will post a photo but it will be upside down.

Hey there..I have a blog post that may help you out.

http://timothyriversinteriors.com/2015/04/21/the-secret-to-decorating-your-dining-room-that-wont-cost-a-million-dollar/

Happy Designing!

Thanks, Timothy Rivers. I like what you said about "Great design is often about blending various periods and style in an expressive yet tailored manner." Trying to get our house to fit into one style or period would be tough. We already have a mix with mission chairs, modern lighting fixture,
tibetan stools, cape cod house, shaker cabinets, dutch arch doorways-
phew!

I find I'm most drawn to rooms which don't seem too constrained to a "cookie-cutter" period/style - ones that don't seem too forced or "matchy". You designers make this well blended style look so effortless. :)

Thanks for the inspiration photos, Drawer Essentials. I really like the color on the back in that photo. I was considering a gray on the back of the shelves and the entry door to anchor each end of the room. Right now the dining area holds most of our darker colors, so I though a colored door on the opposite end might be fun. We shall see how it all evolves.