There are at least six kinds of marble tile at work in this bathroom, seven if you count the lavatory counter. To help these different types and colors of tile work together better, the designer unified everything with a grout color. If you look at the gray border on the floor you can see that the grout colors just a bit lighter than the darkest color tile. If you look at the white field tile on the wall you can see that the grout color's also a little darker than the lightest color. The grout color picks a happy medium and pulls this whole bathroom together with effortless grace.