We never sealed our light colored grout when we built our house, and, over 7 years, it eventually became black. We tried every cleaning product and Pinterest home remedy to no avail. I despised our grout. What to do? Dan to the rescue! He and his assistant arrived promptly, helped move furniture, and worked diligently on hands and knees cleaning and recoloring 900 square feet of grout in only five hours! Our floor looks brand new and is now properly sealed. It looks beautiful and I couldn't be happier!