I had to clean off all the dirt from the floor and on the grout before I can use the colorant. Since I was already on my hands and knees cleaning, I spent some time scraping off some paint that got on the floor.
Then I got out an old toothbrush that we’ve been using for cleaning and applied the colorant very generously to the grout. I realized I shouldn’t have used such an old toothbrush because the sprawled bristles got the colorant all over the place.
The directions said to let it dry for an hour before wiping up the excess colorant on the tiles but classic me, I was too impatient to wait. I very carefully wiped the colorant off the tiles with a towel – trying not to wipe any off the grout.
At the end, we’re pretty happy with the result.