How about a simple subway tile. These are handmade in upstate New York and come different shapes and sizes.

I think Paul F’s vision shows how much lighter the kitchen could be with a lighter backsplash. The linen splash suggested by houssaon is a great suggestion, so I would steer clear of gray. Gray would seem the natural choice with the bench color, however lighter will be more uplifting for the longer term.

I like the way a lighter backsplash repeats/mimics the lighter glass band on the doors.

Are you keeping your walls that off white color?

If so I would do something off white too and simple like a subway tile maybe one with an organic feel

Or its the time to do a beautiful marble continously like a Calcutta gold like the picture another commentor rendered they make porcelain slabs if marble is too much money

I wouldnt do grey unless you can find some that are more varied in color like not a simple grey as I think it would compete with your counter tops that are grey since you will not find anything that's the same

It would be like doing 2 different whites next to each other you can always see which is warmer which is cooler

I would order a peel and stick and play around

There are actually pretty good options out there for peel and stick backsplash now

https://www.wayfair.com/Smart-Tiles--Peel-and-Stick-Gel-Backsplash-Tile-Morocco-11.5-x-9-SM12G04QG-L7271-K~TCPI1232.html?refid=GX679864154051-TCPI1232_85838766&device=m&ptid=1674133829460&network=g&targetid=pla-1674133829460&channel=GooglePLA&ireid=263702601&fdid=1817&PiID[]=85838766&gad_source=1&gclid=CjwKCAiA8sauBhB3EiwAruTRJuZwQlUlAIPqhpHYV79qu4rXG45vF1BPDoqXAneI1uLNUWDlnJYhphoChL0QAvD_BwE&piid=85838767

https://www.bedbathandbeyond.com/Home-Garden/Aspect-6-x-24-inch-Charcoal-Slate-Peel-and-Stick-Stone-Backsplash/11910770/product.html?opre=1&option=18851078

Since your countertops look to have white and grey, it might be a good idea to either do the countertops up the wall, choose a simple white subway tile, or look at a light grey that will work with the countertops. Below we have included a few images of kitchens with backsplashes that could work in your kitchen.

Wine Country Charm · More Info

Scandinavian Delight · More Info

Traditional Renovation: Kitchen · More Info

I like the dark gray that houssaon posted. White is too stark a contrast.

Something interesting but simple.