Discoloration under eyes after facial fat transfer

I had a facial fat transfer 3 weeks ago. Immediately afterwards (ie 10 min), the under eye area looked good/refreshed. But now 3 weeks later, I'm developing rust colored circles under the eyes that looks like melasma. Most of the bruising and swelling is otherwise gone, so I'm concerned this may be permanet hemosiderin staining or something. Has anyone else had a similar experience?