Sounds like the fabric is a digital print. This issue is well known and very frustrating. It happens to longarmers, too. The way it's explained is digital inks sit on top of the fabric, instead of soaking into the threads like conventional inks. As the needle/thread passes through the fabric, it spins the thread so the un-dyed bottom side spins up to the top. I would hope that when the quilt is washed, maybe the threads relax and adjust back to their normal position, but I don't have any personal experience with it.