That's the heifer that did not make it. It was periodically inspected to make sure that only red hairs were found, but just before getting to the right age for the sacrifice, the rabbis found some white hairs. There are quite a few people, both in Israel and the US, trying to breed a perfect red heifer, but so far they have not been successful. I believe that when the time is right, i.e. in the Lord's time, a perfect red heifer will be found.
About a year ago, my son wanted a puppy. Like any other child, he came up with all those good reasons why he needed a puppy. I was speechless when he said that he needed to have a puppy so that if a red heifer happen to wander into our property, he could round it up and keep it safe while I contacted whoever needed to be contacted! Needless to say, I'm now more careful discussing prophecy in front of my young children!