It can either look really dramatic or too dark, depending on the size of the room as well as your other components. I've attached a couple of images of our work using dark tiles, the smaller bathroom we have surrounded the bath with dark tiles but then balance it with an extra large mirror to bounce the light around the room. The larger bathroom we have taken the floor colour way onto the wall but used a different texture on the walls for drama. Hopefully this gives you more of an idea but you shouldn't to nervous of the room being dark, it's where you can create a contrast as well as textures. Look forward to seeing what you go with in the end.

Could you use the same glass as behind your cooktop for behind the sink? Kitchens generally use the same material for all the splashbacks or it can look disjointed. Have a look at photos of kitchens on this site to get some ideas.

The size of floor tile: 300 x 300 mm and the size of wall tile: 300 x 600mm The floor tile and wall tile do not align at all. It looks unprofessional. Should the tiler redo the job? Thanks for your advice.

My initial thought is it May make the room fell narrower doing the short wall opp door. Might be ok if not to great a colour contrast. And if it is beautiful that might be the way to go. -other views?