I think I’d introduce some wooden stools to warm things up and add some texture. Stools with backs are more comfortable than those without. IMO

Is this a Daltile Quartz? I am considering it myself with white cabinets. What did you decide to do?

It looks like a water jet diamond mosaic marble tile, something similar to the tile below, but it’s not the same marble. I’m not sure what stone is in your image, possibly Calacatta Gold.

the corner agaisnt the wall is a bit shadowy/ I'd want lighter /white subway because of the nature of that.....and as well.....the sink area has your beautiful veined pattern on display .......so I'd just stick w white subway. You can pick the size of tile/ how much gloss and any tweak to the grout color.....that's enough / dont need anything more . Not sure how a color would work...but maybe a green subway ? glass? if you desire color. Shaped tile? cant see that so much. Just start w samples since it's sitting ready now.