Recently I put a new laundry room on my main floor. I wanted to put an undemount sink in but did not want to spend the money on a solid surface. So I purchased a formica top , mounted the sink then used an epoxy grout. In order to match the top I went to the kitchen and found three different coca powders. I then sprinkled them onto the wet grout and allowed them to color the grout. once the grout dried the color locked in.