If the quilt is predominately black or dark--I use black batting. The only bearding I've experience was with white batting and bearding isn't "show through". It's where little wisps of batting escape through the needle holes. The bearding stopped after the quilt had been used for a while and the holes tightened up so I wouldn't worry about it unless this quilt is a show quilt.

Unless you've used some thin, very light fabrics, black batting will be fine. Also, Pellon makes a black fleece type batting that won't beard. I saw it at a local Super Joann's the other day on the bolt.

I've only used dark batting for Amish quilts. They are usually dark colors.