Have u thought about a glass splashback?its very easy to clean,I have used red,but u may like a more subtle colour! We put in black granite bench tops when we built the house 17 yrs ago,they still look fantastic but they are a nightmare to keep clean,I would definitely change them to a white Caesar stone if I could!!

This is going to come down to what your space is like, light, how you use the kitchen, how does it relate to other areas of the house ie. is it open plan, so needs to complement other areas such as dining & family? Here are a few examples of backsplashes with concrete benchtops. Depends on your personal style & taste as to what appeals to you. My 1st reaction was marble, it would give interest & movement but without knowing what else you have going on in the room...

I have used man-made stone such as Caesarstone on my client's bench tops for years with no negative feedback thus far. If you are looking at Caesarstone and don't want a stark white, then consider Organic White, Frosty Carina or if your budget runs to it, Calacatta Nuvo (a marble lookalike). If you like grey, before they released their concrete range I used Oyster. I agree with Focus Kitchens & Bathrooms, you would be better to visit a showroom and have a look at a large sheet of any you are considering. It gives you a much better idea of not only colour variation but the overall pattern. If you do use 'stone' on the bench top there is an emerging trend of running it up onto the splash back as well. This works well if your design style is classic or modern classic (transitional).

I'm going to suggest these grey Montage tiles. I think the Como tiles are nice too. Dark grey will add drama and balance out the dark sink. The mixed tones will tie in the variations of grey and silver in the bench tops, appliances and glass door frames. The stone/slate look will add a natural element to complement the wooden floor and balance out the laminate. If you do go for colour, I like Bernadette's suggestion of complementing the glass colour. A tile that looks like pale jade might be nice.