you are supposed to rinse the dye out under cold running water before washing it you should have dyed it waited an hour or so then rinsed under cold water and washed to set the dye may have already mixed/ran while hanging
Take it off the line and rinse it under cold water until the water is clear with no dye in it. Did you use a mordant or fixative in the final rinse after dying. That is something that makes the dye not wash out so much or fade over time. As it is, don't wash it with anything else of the dye will discolor those clothes. Good luck!! : /
