Good upholstery fabrics should crock very little. There is not a lot you can do to fix poorly dyed upholstery. There are color fixatives that can be applied to the material; the Rit Color Stay Dye Fabric Fixative I mention in the article above comes in an easy spray bottle. But they all require you to rinse the product out; if the fabric can't be removed, this could be very difficult to do. Also, it will depend on what type of material the upholstery is, as color fixatives don't tend to work well on polyesters.