Can a top coat be used on freshwater pearls that are not colorfast?
Using a top coat on pearls is generally not recommended as it can result in reduced luster or worst-case, potentially cracking the surface. Rinse your dyed pearls thoroughly until the water runs clear. Let the pearls air dry for at least one day before handling them. Properly rinsed pearls should not release dye. Dyed pearls can fade with time and wear. Be sure to store pearls lying flat in a porous pouch. If you desire, you can re-dye the pearls to bring back the vibrancy. For instructions on how to dye your own pearls, see the resource below.