What about washing it with Synthrapol? This kind of works the opposite way to retayne (I think). It washes off all of the excess dye particles that Prism99 is talking about. I've used it when some colours ran into the white on a quilt and it got rid of all of the excess dye.

Synthrapol suspends unset dye particles in water so they don't settle into fabrics. Bleeds are not permanently set, which is why Synthrapol can work to get rid of bleeds. This is why Synthrapol works well when washing quilts. If there is a bleed, Synthrapol will keep it from settling into other fabrics.

However, Synthrapol will not permanently set unset dyes. A fabric that has unset dyes will continue to bleed after many washings. It's a manufacturing defect. Retayne will permanently set dyes, including bleeds. This is why you never want to use it on a finished quilt. If there is a bleed into other fabrics, Retayne will permanently set the bleed.

When I had a black fabric that refused to quit bleeding even after vinegar wash I decided to try something else, if it ruined the fabric it would be no loss as it was unusable the way it was. What I did was put the fabric in the biggest pot I have, fill with water, put on the stove and boil it hard for about 20 minutes. It didn't hurt the fabric and it did stop the bleeding. The finished quilt is black and white, has been washed several times, and the white is still white. No more bleeding.

If you use the retina and afterwards it can only be cold washed if this quilt for a small person whose mum will wash in warm water will it be a good idea?v
Just a thought after reading people's comments.