There are several options for backsplash to use with Grey Granite countertops:

1. White Subway tile: A classic choice that will complement the grey color of the countertop.

2. Glass mosaic tile: Adds a pop of color and texture to your kitchen while complementing the grey granite.

3. Grey Subway tile: For a monochrome look, you can choose grey subway tiles that match the countertop.

4. Marble tile: Another classic choice that portrays a luxurious look.

5. Stainless steel: A contemporary look that presents a sleek and modern appearance.

6. Slate tiles: A natural choice that resembles and complements the grey tones in the granite.

Overall, the choice of the backsplash depends on your personal style and the overall look you want to achieve in your kitchen.