Fabric Dye Transferred in the Wash?

I washed "hand wash only" dresses on the gentle cycle and tossed in a new dress, black and white tie-dyed, that was never washed before. It bled on all the dresses, really badly on an ombre pink colored tube dress and a pair of gauze material palazzo pants that are cream. How do I get the black/grey streaks out? They are currently soaking in cool water with laundry detergent and vinegar. Please help.