Can floor grout be painted?

I had my house retiled with tan tiles and dark brown grout. The grout turned out much lighter and grayer than the grout sampl. Looked pretty bad. So I had a different company seal the grout with a "dark chocolate" sealant. It turned out darker but still had a grayish tone and was not a match to the sample even though it was from a different company. Can I paint this sealant with some kind of paint so it will look like a Hershey bar? If not is there any suggestions on how to get the grout lines a dark brown like plain old chocolate?