We have just had our bathroom tiled with 300x600 white ceramic glazed tiles. 2 days later they have all turned a varying shade of grey. The tiler has never seen anything like this before. He used grey adhevise and white grout. The tile shop claims that tiles are not faulty, and that they will turn back to white within 5 days (which they haven't).
Has anybody ever experienced anything like this? Any advice.