albino
Albinos occur naturally in all species occasionally, including humans, so truly wild white rabbits can occur.
We have found 2 white rabbits near us, not together, but almost certainly dumped domestics, because at first they were clueless as to how to live and wandered about helplessly on the road. We tried a few times to catch the first one we found, but it scuttered into deep undergrowth each time. It manages its life much better these days, but as the weather gets colder we are worried for it. My mum is bringing a rabbit-catcher down next time she comes, in a couple of weeks, so we'll see how it goes. We think they were probably dumped together on the side of the main road, then scattered in fear in different directions. But we will never know the truth.