I haven't read all the posts so maybe someone already mentiond this. You could snip off some of the fabric and put it in a glass filled with warm water and let it sit there for 20 or 30 minutes. If the water turns color dump the water and do this again. Keep repeating until it stops running. I suppose if it is running still you could wash that one fabric alone with a color catcher and repeat the above to see if it still runs. You probably won't end up with fabric running but this is one way to check ahead of time before washing.
With all the fabric you are using maybe this isn't a great idea but thought I'd put it out there for you.