They are stained like the rest of the kitchen cabinets.

Thanks so much for the clarification. We are doing a mini reno to our kitchen and adding a peninsula, new countertops, backsplash, under cabinet lighting. Having the outside perimeter of the peninsula match all of the existing warm medium cherry cabinets seemed too much and potentially too dark, especially since our kitchen is the north side of the house. We aren't replacing our existing cabinets because they are relatively new and in great condition and timeless (plus I like to be green where I can). So, we were thinking of doing something like this which we really love, but weren't sure how to incorporate the addition from the inside without it looking odd.

Thanks for thinking outside of the box and offering alternatives to those of us that have a lot of floor space in the kitchen but not quite enough to fit anything other than a really skinny island of no use. This allows us to provide for countertop seating for my family and offers us a great opportunity to create lots of memories cooking and creating together at the peninsula for years to come.
:O)