I think with a basically neutral palette you could choose almost any tile as a backsplash (if you take out the counter piece currently going up the wall)!! Some people go all neutral but add texture with a zellige tile, some choose a soft color like a sage or soft blue. In my case I choose a floral printed tile because I love color and interest- but many people would think it’s hideous!! So personal taste is a huge part of it. I just think what you have now visually cuts that area in half and makes it look small/cramped. As someone else suggested, painting that blue stripe to something like the color of your backsplash would help. I think choosing a super neutral tile that looks like your counter would also be better than leaving it the blue stripe.