I am wondering if anyone knows of a retailer who sells a product called "LIQUID GROUT". My father-in-law used it about a year ago and purchased it from QVC. They no longer carry it. It is a product that colors existing grout.

Anyone know where to buy? Been searching on the Internet with no luck.

Haven't heard of that particular brand but this stuff may be what you are looking for. Kits (http://www.groutdye.com/kits.htm)

Two other sources for grout colorants are Grout cleaning, tile cleaning, grout cleaner, grout sealer, grout colorant (http://www.thisoldgrout.com) and Aqua Mix - Home (http://www.aquamix.com)

Here's an excellent instruction resource on doing the grout colorant:

http://www.floorstransformed.com/ceramic-tile-forum/2007/grout-colorant-25283.html

Prior to using a colorant, your grout must be free of any dirt or sealers. High alkaline cleaners are good for removing sealers or other coatings, such as Tec's "Like New" cleaner. The grout colorant will recolor and seal the grout all in one step.