I have seen and heard of patients that have these kinds of tissue transfer flaps have the tissue change color a couple times early in the process. This is a function of the new vascularization of the tissue. They seem to start out pink, turn grayish and return to pink as the new micro vascularization occurs and reflects the changing tissue as the blood supply changes.They also seem large at the beginning and ultimately get somewhat smaller as they heal in. I have not talked to anyone that has had this happen far into the process and I think you need to see your doctors soon for their take. Causes for this might be an infection that has taken hold, either bacterial or fungal.

I hope someone joins in with some direct experience. I wish I had a better answer for you. Please come back after seeing your doctor and let us know what this was and what the solution to it is they are going to apply. It will help us understand it better, to in the future help others. I hope you find this is something simple and easy to deal with. Wishing you the best. B