Most tile jobs include areas that are very difficult to grout such as corners where tile meets tile or places where tile abuts against cabinets or other similar objects. Colorfast caulking is ideal for this because it has been formulated to permit for the settling of joints by being able to flex. Don’t worry about your Caulk matching your Grout; Colorfast Caulk’s are available in the same 36 colors that Keracolor U Grout is offered in. Contact us to request a FREE MAPEI color chart. At MAPEI, concern for the environmental impact of our product is more than a trend; it is a fundamental part of our philosophy, corporate commitment and industrial responsibility. MAPEI leads the industry with the largest selection of ecologically friendly products available and is proud to have them exceed LEED (Leadership in Energy and Environmental Design) standards. When you see the BioBlock symbol, you can be confident that the product you have chosen is solvent-free, non flammable, extremely low-TVOC and low-odor.