3M High Strength Color Changing Wall Repair goes on blue and dries white, helping identify when a repaired surface is dry and ready to be sanded and painted. Eliminates the guesswork and reduces the chance of errors. Its ready-to-use formula dries quickly and provides professional-looking repairs. Kit includes Color Changing Spackling Compound, 3" putty knife, 4" drywall repair screen and sanding pad.