When you are cleaning tile and grout and find that they had some work done to the floor and the tile guy matches the color of the grout to the dirty grout. You then clean it and it now has the opposite affect. Clean grout next to brown colored grout. Good thing I carry grout stain with me. Unfortunately I think the grout was bone and the closest I had was Quartz. Either way , it was fixed for the impending sale.