I would stick to the same color group each time. We have the taupe in both bathrooms and it looks different in each. In one rather beige, in the other more grayish. This is probably also due to different lighting, but we really started doubting ourselves. I think there is already enough "variation" in the tiles, so I wouldn't work with different colors as well. Personally, I would even keep the format the same. We have had walls and floors with 60x60 tiles for 1 year, and we might even lay the same in the house again because we like the tile. Baseboards were cut from the tile, everything looks nice.