The main question is, my carpenter wants to replace the main stairs with Walnut wood for the riser and White Oak for the Runner. I have not seen any examples of this so I am hesitant. But I think this might look really nice. I need advice...

The main floor will be White Oak and the accent wood will be Walnut. No staining for either wood, just natural wood. The accent wood will be in the fireplace room book case shelf, knee post shelf at the room dividers, and the tiny trim between the base board and the floor. We are thinking of white spindles and a walnut hand rail. So the Walnut should have a theme within the first floor decor.

My significant other want white riser, but the carpenter said they will get dirty fast and you will be repainting them regularly. For myself, I like the pictures of white risers in large homes, but my house is an old farm rectangular house that has been modernized. I do not think the white risers will look nice. The other option is just doing the entire stairs in White Oak, but that seem boring now.

We are under construction and the decision is upon us, I do appreciate any help of suggestions.
Thank you,
Ron