The colors are off on my monitor.

Have you looked at Jasba Loop penny tiles? They have a line with a non-slip surface for floors. I have the glossy in Denim and that would work beautifully with that wall tile. They also have a dark blue and an aqua. I'm not sure if all colors are available in the non-slip. It's a German company but my tile store gets their stock from California.

Daltile has a derp blue penny round. Only in person samples will show if it can work with your wall tile choice.

I found the photo we took at the tile store. The non-slip tiles are called Secura. The mixed shades of blue were gorgeous. I think the mixed shades are Centino and the solid colors are Loop.