It's common for people who have put in a white kitchen to feel that it ultimately is lacking in color. This would be a place to really add some color back into the scheme if you wish. An alternative would be to keep the backsplash understated and then use rugs or other items to add color to the decor. Don't rule out pastel-colored shutters, either. It's a bit hard to see from your photos, but tile all the way to ceiling and including behind floating shelves is a lovely look if your tile can technically sustain it. Glass or other fragile tile won't do well with being fitted underneath a floating shelf, but most porcelain tile will do fine with that. It's tricky to tile around the shelf, so most tile in that application is applied underneath and then the shelf fitted on top.

Nice job so far! I’d make sure that shutters can actually work over the faucet (door clearance). Are you trying to block the view or have privacy in the daytime? If not then I’d consider a Roman shade in a natural look to continue the warmth of the wood accents you have and to draw your eye higher on that wall. Really any of your inspiration pics would look great as the backsplash. I’d say bring home lots of samples to test in the space and then post a follow up pic for more accurate responses.

Shutters will also block more light, so If you're open to other options, I'd keep what you've got there.

For the bs behind the sink, have you considered continuing the counter material up to the window? Ask your fabricator if he can make a piece to fit.

For the rest of the bs the classic choice would be a grey that matches your veining in the counter material. It's a very pretty, traditional space, so I'd be looking at traditional or large format subway tile. This is Fireclay Tile in French Linen, but you can find something similar in many other tile lines. You can of course use this throughout, but the window area is special - it can take its own treatment if you like the idea.

Cindy Lofton ! I need your help badly, your kitchen is basically what I have chosen haha and is love your feedback on what white cabinets you went with and how white the laza looks against your white cabinets ? I have kraftmaid dove white. Also, where are you located? I’m having the hardest time finding slabs in person.

Also, Cindy did you need any seams in your countertops ? They are saying laza doesn’t book match