Your window decoration is cobalt blue and cobalt blue glass tiles would look great as the backsplash...whatever you decide after reading all of the great responses you'll get from Houzz readers, have fun choosing!

I agree with cobalt blue! It would add a great pop of color to your kitchen!

If you've got grey on the wall already, I would avoid any more grey. Blue would be nice or just stick with white because it's so clean. If you wanted to warm it up you could do a bright warm color like orange or red to make the blue pop and keep the grey from dulling it down. But if you're deciding between white and grey tiles, I would do white.

Have fun with a pop of color. Do you prefer warm or cool colors?

Ted, I live blues, purples and reds. Want to accent with them but not overdoing it.

The only thing that will make it look dark is lack of light. If your cupboards do not already have undercounter lighting installed, add this to your to-do list.

You can add glass mosaic tile with pops of blue glass tile peppered through. Agree that you need under cabinet lighting.

I might suggest white glaze glass subway tikes with accents if cobalt blue. This application will provide a clean look and still adding a pop of color and interest with the blue accents.
Another option you can view on Overstock is SomerTile 11.75x11.75-in Samoan Subway 0.5x1-in Neptune Blue Porcelain Tile.

I do not think a blue backsplash will be overdoing it. What is the name of your granite? Do not choose paint color until after backsplash is installed.

This is avery small space I would not do a accent tile behind the stove since it will just break up an already small space for backsplash . I would go white glass tile and then use the blue for accent pieces like a kettle

I would do your backsplash one colour only. But if you love blue, use it. I had it in my kitchen before our reno for 10 years and loved it. When we reno'd this year, I replaced it with more blue tile that's even prettier. I admit the look isn't for everyone. But you're not everyone and it's your kitchen.

My tile is St. Alban's blue subway from Fireclay.

I agree with Jennifer. I think the blue tile she picked was lovely, as well as Debbe Daley Designs. As soon as I saw your kitchen I thought, ooh blue! Then I saw your light and thought blue would be great. Later on you can switch out accessories in a variety of colors like white, red, yellow, orange. Yes, blue for the win!

Thank you everyone for your input! Emmarene, my countertop is Vizage Blue and the paint will match the light grey in the granite. I've decided to go with 3x12 white glass subway tiles (my counter space is L shaped, I showed the long side in the photo). Jennifer, your tile color is fabulous and I will find accents in that color - I'm also considering using it for the over-the-stove tile. When the range hood is installed I'll have a small space for that accent tile, about 3x1.5. Under the counter lighting is a great idea and I'll definitely add that.