My walnut floors have already faded, and they have only been in a little over a year. However, most of the kitchen is exposed to light, direct sunlight in the winter months. Our older walnut furniture is a bit lighter than the floor, but I forget how dark it was from the start. I'm pretty clueless about UV inhibitors, but I'd do a UV inhibitor before I would stain it. Oil-based finishes will naturally bring out the amber tones in the wood, making it look more red and orange. Water based finishes don't bring out the oranges and reds, but sometimes leave a bit of a cloudy look behind.

Thank you for your advice! I still have time but wanted to be prepared with questions when I meet the cabinet maker this week.