If a puppy yorkie has a white spot on foot is it still a full breed?

I am looking into getting a yorkie however I'm wondering if the dog Is full breed. The mother is akc and dad aca I was reading online that anyone can go thru the akc or aca and register their dog. If this is tru how can I determine if this dog is a full breed. Also, the puppy has a white spot on it's foot .... Is this normal of a full breed ?