I've seen a kitchen where instead of a tiled backsplash the black countertop was continued up the wall about 10cm, and the wall was painted a rich deep red. It looked fantastic.
You might also consider a deep rich "art deco" pink (something like no. 61 in [broken link removed] image), which would work very well with the black and white.
If you do go for a strong colour you only need to use it on one or two of your walls, you can paint the rest of the walls white and use pictures to add colour to those walls. (I have a black and white kitchen too, and I have white subway tiles as a splashback and all the walls are white, but I have bright coloured pictures on the wall - including a large predominantly aqua blue map of the world - to stop it being too monochrome)