This totally depends on your ability to color and style match:) If you have pice of the original take it to a professional tile showroom and have them locate something as close as they can. I am not sure your location but sometimes you can have new tiles made from scratch to match also. If this is not an option you can get creative with the floor you have maybe add a border or something to mix the new tiles and the old ones so they look like they were meant to be together:)