Just recently finished tiling and grouting the bathroom which i must say have not done a bad job after noting help from a previous post i sent, but my only problem i now have is the white waterproof grout looks beautiful and white when dry but when the shower has been used the grout goes a dirty looking light brown colour until it drys out and then it is perfectly white again, i know grout, even waterproof grout soaks in a certain amount of water but i would like to know is there anything i can coat the grout with so it keeps it lovely whiteness even when wet. someone i know suggested some sort of clear varnish or nail varnish which i think may work although time consuming (whch i do not mind if it works) or does anyone know of a different way of doing this.