I recently posted that the Dolorean Gray grout stained my floor tile blue and Bill V suggested Hydroment Grout Haze Remove. Well, I hunted that down and my contractor used it and it really helped. THANK YOU.

Also they regrouted using who knows what kind of technique - I was at work and missed the actual event but when I left for work, they were taping the tile edges and presumably used some kind of method that really targeted the grout lines. Anyway, I'm happy with the way it turned out and thanks for that product recommendation Bill.