My Holland Lop is 1.5 years (about) and is black. We brought him to live inside this spring. For the last month or so, he's been shedding his coat. I'd say he's at the peak of molting right now. My question is this: his black fur is turning white on his back. It's also shorter than the rest of this hair (I'm guessing it's new growth). But why the color change? Is this normal?