Why are my grafts so much darker than my native hair?

It would be unlikely that your hair follicles were mixed up with other patients next to you.  If you are concerned it is best to address your issues with your doctor.

Your transplanted hairs should be similar in color to your native hairs.  The miniaturization process tends to make the native hairs (the DHT susceptible hairs) a bit lighter in color, but there should not be a huge difference. Go back to your surgeon with your questions for added clarification.

The Color of transplanted grafts should be like the hair in the back of your head. Sometimes blonde people will get a darker brown until they get enough exposure to the light to lighten it,