How about using the material on the wall at the end of the dining table for your backsplash? It looks like bead board or planks painted that lush brown..this would tie the two areas of the kitchen together and not compete with the floor..

Any possibility of using a dark brown backsplash and counter?

How about dark glass tile? It would bring the terrazzo feel on to the wall.

Is you like the terrazzo, pick one or two colors from that and brighten up the kitchen with those colors. For instance, from the photos you seem to like red. Why not find a red what's close to the terrazzo and perhaps another color an add some pizzaz to the kitchen? It's really all about what you like.