Something like this?

http://www.tstmosaictiles.com/TST-Glass-Stone-Tiles-Black-Dark-Grey-Squared-Grid-Marble-Kitchen-Backsplash-Inner-Crack-Mosaics

Have
you considered using a stainless steel mosaic tile to bring together your
black and white countertops?

Eden Mosaic Tile Installations: Random Mix Steel - Glass II Tile · More Info

Eden Mosaic Tile Installations: Stainless Steel And Crackled Glass Mix Tile · More Info

Eden Mosaic Tile Installations - Modern Trapezoid Stainless Steel Tile · More Info

Eden Mosaic Tile Installations: Large Brick Pattern Mosaic Stainless Steel Tile · More Info

Eden Mosaic Tile Installations: Brick And Square Pattern Stainless Steel Tile · More Info

We are a premium online supplier of metal mosaic tiles
for backsplash and other wall applications. If you are looking for ideas, feel
free to browse our customer installations for metal backsplash ideas:

http://www.houzz.com/projects/72838/eden-mosaic-tile-installations

You can also check out our Houzz store at:

https://www.houzz.com/pro/edenmosaictile/eden-mosaic-tile

We offer the possibility to receive samples.

Good luck with your kitchen design!

I think a sea foam green glass tile would look nice with the color scheme and style. Something similar to this:

Eisner Design · More Info

Contemporary Kitchen · More Info