We are progressing with our master bathroom remodel (it's the royal ''we'' as ''we'' are not DIY'ers with respect to this project). We talked to our tile guy yesterday a little about grout color. Tiling won't start for another week and a half or so, and we therefore have some time. But I wondered if you guys had any opinions about grout colors for the 2 widely different tiles we are going to use.

This is the field tile:

This is the accent tile. It will be on part of one wall in the shower and also as the backsplash:

There will be a lot more of the field tile than the accent tile. I'd like the grout to sort of disappear with the field tile, but not sure how that would go with the glass tile.

I know this is hard with different monitors etc. but I'd welcome opinions, if anyone has any to offer.
TIA