I usually wash but sometimes get lazy... I helped my daughter finish a beautiful baby quilt with black in it. She washed it with color catchers and it bled badly!!! I had some SYNTHRAPOL which I put directly on the spots and washed again. It completely came out!!! I recommend using it to set the dye in your quilts. Here is the site:
http://www.dharmatrading.com/html/eng/2127-AA.shtml