I just recently had a new tiled shower installed. Our contractor used a ceramic tile and a linen color grout. When the job was finished, I waited a week to use it for drying purposes. After I started using it, within a week, the tile floor grout stayedlooking wet in scattered areas. It looked a dark gray color. I stop using the shower for a couple weeks hoping it would dry out, but it has not. It just keeps getting worse and the contractor is stumped. He thinks it is a drain problem. Any advice would be appreciated.