The obvious choice for color would be a blue that compliments your bs. I don't think you need color so much as LIGHT. Install a couple of cans over the island so you can actually see in there. If you want some visual interest, consider wallpaper with a damask or geometric pattern for that wall.

I'd pick a slate blue or similar color as long as it goes with your backsplash (can't tell from the picture). I'm not a curtain fan. Unless your neighbors are very close, I'd go with a bit darker paint and no curtains to bring in light and show off your pretty windows.