How will the tile be set (or, where will the "border" be located)? I wouldn't use a border tile, instead use a Schluter edge either in a soft grey or the color of the tile.

No black border. White Schulter where needed. I’d rethink the black shower hardware too, hard to clean.

IMO tile borders are not a good look usually the draw attention to the things that best are invisible and a nice simple schluter is white or stainless is almost invisible . I agree about the black fixtures they show every water mark and honestly trendy . You are spending big bucks to do this a classic chrome is just classic LOve the tile and honestly it is the star and in bathrooms simple few finishes are always best. I aslo would suggest no niche, shampoo bottles are never decor and a nice caddy is easy to clean and never cuases issues with waterproofing , which BTW is a huge must to get done right so the best bathroom pro tiler you can find .I like the metal schluter but it needs to be discussed with the tile setter since the best is the trim thta goes on before the tile so virtually invisible.

As per Hallett above. I will add.... nothing but nothing will outlast polished chrome plumbing in a bath or be easier to keep sparkling. You want black? Save it for accessory items, hardware, lighting, mirror frame etc. where it will be easy to trade when the FAD of black will die.....

Simple clean inconspicuous Schluter....for edges. White.

I appreciate all your comments. My husband was pushing the black schulter but i like the white. Definitely going with white. I think I’ll stay with the black fixtures for now and them swap when I get bored of them. (I drive my husband crazy with the kitchen hardware). I will post pics to share my progress.