Donor area hair is noticeably grayed out right after FUE! What might be the cause? 1 month post op.

Greetings Doctoers! My colleague and I decided to go for FUE, and as of today it’s been 30 days post surgery. At lunch time my colleage noticed that I start developing gray hair in my donor area, which I confirm absolutely wasnt there before surgery. I’m wondering if this is common condition is some patient? Is it a short term side affect or permanent? What might be the cause? Dr. Thanks much for any suggestions or recommendations!