Things You'll Need
Clean rag or sponge
Small, stiff artist's brush
Grout stain and sealant combination
Grouting mistakes include colors that dry darker or lighter than expected or mismatched grout and tile color. A grout color change is also an inexpensive way to change your decor. No matter the reason, your grout color can be changed using a grout stain as long as the grout installation is dry and clean. New grout installations must cure for a month before staining. Note that while lighter grout colors are easily changed, darker grout colors can not be lightened.
Choose a stain made for grout. Use a product that combines the stain with a sealer for a single-application grout staining process.
Begin with a clean surface. Clean the grout using a scrub brush and an oxygen cleanser. All wax, dirt, debris and oil must be removed for the stain to penetrate properly.
Allow the wet grout to dry for at least two days. Damp climates may require an extra day or two for complete drying.
Apply the grout stain directly to the existing grout using a stiff artist's brush.
Use a sponge and wipe across the tile surface to remove excess stain. Stain that is not removed from the tile quickly can permanently stain the tile. Unglazed tiles need immediate attention.
Allow the grout stain to dry according to the manufacturer's directions.