I cleaned a area with pure bleach and it didn't change its color. I put a fun on it for two days thinking the grout couldn't dry out because I have done so much work on it. I wonder if the phosphoric acid cleaner caused a problem. I'm getting really upset with this tile. I love the tile, but I don't have enought time to keep working on it. I want closure so I can get other things done and I have to go back to work when I won't have the time. I don't know what to do!!!! Pegggy