Help?

Oh, it has happened to me!  And I need to remedy it.  And I do not know how.

I made a little baby quilt using Kona white and batik scraps.  I had always heard that one need not pre-wash batiks, that they were colorfast. 

I put my finished quiltlet in the washer and when it emerged, the dye from some of the blue, the purple, and the orange batiks and bled into the white.

I have heard people speak of something called a dye magnet.  Do you know anything about this?  Or is there something else I can do to get these colors out of the white?

Strange that this is the first time after all these years.

THANK YOU TO ALL WHO SUGGESTED COLOR CATCHERS.  I SHALL GET SOME FORTHWITH!!!

Thank you.