I think a light gray glass backsplash would be elegant.

is the color of the granite actually white, or more of a creamy white? in the photos it really looks yellow but I don't know if it's your lighting.

so here's a chevron 2x9 in a creamy that matches in the pic

and here it is in either a white or pale gray just in case the stone is actually white

some other options

this is basalt in a herringbone and is a dark gray/charcoal ini person.

these are 2x8 and come in white and gray

white marble

cletiles is having a sale on their cement tiles. 1/2 price for these. they are black and white, but I can only copy the photo in the blue and white.

https://www.cletile.com/collections/cle-holiday/products/moroccan-encaustic-cement-tile-xtra-credit?variant=&variant=41225587206

these patterns too

notice the white subway tile as well as the cement in the foreground

rachelle, since the tile will be next to countertop, match it to that. if you could find a good middle between white/cream, great. or just pick the darker gray/charcoals.

I’d go with something in the cream family that matches the lightest color in the countertop, and go with a fun shape. Tile all the way up to the ceiling so it’s tile behind the vent. No mosaic - too busy with countertop. No dark colors - you already have enough of that. No subway tile - do something different.