I've had dye transfer from one fabric to another when they touched. The water was clear, and there was no bleed where two fabrics were pieced next to each other, no fading, but dye was splotched where the dark & light fabric touched. I'm guessing when it was (gently) wrung or the water drained and the weight of the wet quilt pressed the 2 sections together. If you catch it before it's dry, you have an opportunity to remove the spots. If you've dried it, your chances lessen.