They are salvageable. The dye that has moved into other fabrics has not been permanently set, so it can be removed.
What you need to do is create your quilt with these blocks. Do *not* prewash the blocks, as you can have a real mess on your hands if you try to do this (aside from fraying, the different fabrics in the blocks can shrink differently if they are not already quilted to a batting).
Once the quilt is quilted and bound, wash it in a machine that uses *lots* of water and throw in some Synthrapol. Synthrapol is widely available online at places such as Amazon, and carried by quilt shops that cater to dyers. You will need to wash in hot water to make sure that the Synthrapol is activated. Synthrapol acts to lift and suspend loose dye particles in water, so the loose dye is rinsed away. Occasionally you may need to wash two or three times to get all of the loose dye particles out. Examine the quilt before drying to see if you need to wash again. I would take a close look at the light fabrics, as they will be the most obvious.
Here is a link to Synthrapol on Amazon (it takes only a small amount for each wash):
http://www.amazon.com/Jacquard-Synth...dp/B0009IJZPY/
You can add color catchers also, but Synthrapol is the primary requirement.