We finally picked our backsplash tile, an antique white subway tile. The grout will be a similar shade to the tile. The tile store said they sell an additive you can mix in with the grout that will make it stain proof. I think its called Boost, it sounds too good to be true. Has anyone used this product? Or am I better using regular grout and then sealing it with a quality sealer? I had originally thought of just using a dark grout, but I like the look of the grout and tile matching better.