I am not familiar with grout bully but I have used grout dye to change the color dozens of times. Just do some research and find a good one. Dont use cheap priced ones as they are weak and ineffective. It may take 2 applications to cover.If the grout has previously been sealed then a dye cant be used as it wont penetrate the grout. The good thing is the dye is also a sealer if the grout was not previosly sealed. The dye can last for 15 years and will give a uniform color look .

I have tried it once before, and it is kind of a cheap product, but it does the job.

I have used it to cover up the dirtiness look on my grout and it worked pretty good. I guess we'll have to see how it looks in the long run.

Bob, I have used Grout Bully and I thought it was fabulous. Now I am looking for a good sealer. Can you suggest one. GloriaPav1@aol.com

Gloria..Typically when you color your grout with a quality grout stain, it seals the grout as well. I have heard of the grout bully but have never used it so i don't know if that is true in this case.