To my knowledge, it is nearly impossible to match tile unless you have tiles from the same dye lot as the original tile. We had tried for our house, but never had any success.
We finally gave up, and the builder had to replace all of our tile just to fix two areas that had cracks running through them. They were NOT happy!
Also, be sure you find someone to do the installation that understands the movement required for our floors...i.e., they use the right kind of subflooring and grouting. Wish I could help you with that search...
Take good care!