follow the instructions on a bottle of retayne---and throw in a couple 'color-catchers' from Shout- in the grocery store laundry isle. if the color catchers come out with color- rewash the fabrics- or sort out-figure out which one is the culprit & re-wash that one- rewash until there is no more bleeding before using in a quilt that will be laundered.
i pre-wash all of my batiks---in a normal wash- with warm water & my regular detergent- some people (baby them) alot more than i would ever consider- i figure if they won't hold up to a regular wash- they are not going to hold up in a quilt....but that's me. when there is no bleeding apparent i toss them into the dryer- again on a regular cycle- i do not use fabric softener on them- if i might decide to use a fusable with them fabric softener can affect how well it works.