Easy-to use waterborne epoxy that recolors, seals and rejuvenates existing grout joints. The Aqua Mix Grout Colorant kit contains Aqua Mix Pre-Treatment cleaner, Aqua Mix Grout Colorant brush applicator and an 8oz bottle of Aqua Mix Grout colorant. After the tiles are scrubbed, the color is brushed on and left to (almost) dry. Then a nylon mesh pad is used to remove Grout colorant from surrounding tiles, leaving the lines a brighter white or an entirely new color. Results should last up to 15 years, according to Aqua Mix.