Grout is used as a waterproof material to secure ceramic and stone tiles. Over time, grout color can become inconsistent due to poor installation or maintenance.

Installation
If the grout mix isn't properly blended, inconsistencies in the mix can produce color differences. In addition, if the mix contains too much water, or is not allowed to dry completely before sealing, discoloration can occur.

Stains
Grout is a porous material that contains tiny voids. Things such as foods or colored bathroom products can enter these voids and leave stains if they are not cleaned immediately, leaving color discolorations in the grout.

Mold and Mildew
Without proper cleaning, grout can be subject to mold and mildew, appearing as brown-colored patches. Grout should be cleaned regularly to prevent the growth of mold and mildew, especially in constantly wet areas such as bathrooms and showers.

Cleaning
Some chemical agents such as ammonia and bleach can leave grout with a yellowish coloring, and should be avoided. Always check the installer's or manufacturer's care instructions for appropriate cleaning products and methods.

Prevention
Sealant should be applied to the grout surface as part of the installation process, and approximately once