I am assuming that when you say ceramic that you mean tile.
Given the "pillow" profile of ceramic tiles, I would not recommend trying to lay any type of material over it. Consider having the grout professionally steam cleaned and then have the grout color sealed, again by a professional. This will bring back the color of the grout assuming that excessive bleach products have not been applied to the grout and pitted it.
Alternatively, you can replace the counters. Just remember that your backsplash will likely have to be replaced too.