Thy have a stain you can paint your grout to most any color you want.

Thanks. I've used that before on some floor tile and it is like a rubbery paint that is very hard to get off tile. Unfortunately in this application I have the round river rock so to use the grout recolorant I would have to try to paint around all the rocks. Also it can come out a bit streaky because of it's rubbery consistency. I did buy a test bottle and tried it on my test grout board. It was a chore to get it off the rocks and impossible to only get between the rocks.

I have a granite counter that was installed many years ago. They used a stone enhancer that turned the white parts yellow which is what we wanted. Unfortunately the place is out of business but I was hoping someone here had some experience with a similar product.