I agree, hubby is wrong. There are two selvedges.
Having said that, I have been known on occasion to use the bottom selvedge, the one that isn't white, in a quilt. The edges end up in the seam allowance and you can't tell. The only reason I can think of why you might not want to do this is because the weave is a little thicker and stiffer there, and it might cause a longarmer problems. However, I quilt my own and haven't had a problem yet.