Please let the tile collect some dust or have hairs on it. Then simulate a corresponding light incidence. I also quite like black, but based on experience, not on the floor, at least not a uniform color.
Take your floor plan and transfer it to a sheet of paper. Place it in the center of the paper. Imagine the floor plan in 3-D and unfold it completely. Then draw the respective wall “unfolded” along with the sanitary fixtures as a top view. Now you can arrange the tiles with colored pencils and try it out. I hope I have explained it somewhat understandably. :rolleyes: