I think your backsplash looks great. If you choose a grout color a little darker than the tile, it gives the tile more visual texture on the wall. If you match it perfectly, it looks like a slick wall of tiles. If you go much darker, your tiles will look like bricks. I think it's a personal preference on the color of grout you choose, and you backsplash looks great as it is. I would live with it for awhile. I think once you have all your accessories in the kitchen, and your kitchen is completely finished, you will end up loving it.