It is odd, but its not normal hair like grows on our head, that grows and grows, nor is it fur, that grows to a specific length and then stops until it is shed out. Its a mutation when you get right down to it. Its a hair that would not normally grow, but does, and then it molts out. Further mutations have created English Angora where it doesn't fall out anymore either, or not very much. And that coat has almost no guardhairs. Its unique to these rabbits in what I can discover. Long haired dogs, cat; Wool on sheep, goats, alpaca, also stays the same color throughout. I dont know why rabbits is different but it most definitely is, because you watch the angora lighten in color as it ages. When a chocolate french is born, it looks chocolate. As it grows up the face stays the same color but the wool lightens and lightens. And its not darker close to the skin, the wool is just one color, outside of an agouti.