You're probably done with your project already, but if you went with a walnut color I think you made a good choice. It's modern but not too dark and will not go out of style. Ebony shows everything, especially dust, and grey is trendy now but may go out of style. What stain did you choose?

Any idea, how walnut compares to coffee brown or antique brown? are they of similar shades? My builder does not provide walnut stain, but do love special walnut stain photos I saw in houzz. Sorry I did not mean to hijack your post. Walnut is definitely a good choice and am also in similar situation and need to pick a stain for my new build.

Many companies make several shades of walnut stains, such as dark walnut, modern walnut, special walnut, etc. I would say they are all similar to antique brown. Coffee brown is darker than all of them. You can always start with one color and mix other colors in to get your desired color. I wouldn't worry so much about the name of the stain color, just make sure they put samples down on the floor for you until you find what you want. Really just about any color can be achieved by mixing stains.