Dolce Gabanna Pantone Necklace

Reposhing this item I purchased. I love it, however I didn't notice that a bit of enamel (I think that's the correct term) was missing on the chain before I accepted the item. I hoped to fix it, but I have no idea how. I'm including a picture of the chain that wasn't in the original pictures. I hope someone can fix it and return it to its original glory!