I would leave as is or add a stainless steel sheet, which won't look patchy and will compliment your hardware.

4x4 on the diagonal would look just fine. I have a similar area in my kitchen. Will try to post a picture later.

What about a 2x4, 2x6, or 2x8 tile? These sizes are being used a lot right now, and are very classic looking. The 4 x 4 on the diagonal is a bit dated, in my opinion.

If it's dry, vertical strips of wainscoting would look nice.

How about something like this? Its a 6"X6" honed crema marfil, 1"X1" mosaic and honed crema marfil subway. Something different?

Casual Elegance - Scripps Ranch · Еще

I do not favor mixing a beautiful granite with a ceramic tile. If you add a backsplash I would go with the same granite on the counters. Other option would be to repaint to a color that is in the granite not the blue.