When a hair follicle is transplanted into the scalp, a tiny incision is made with a specialized instrument in the scalp, and the hair follicle is inserted into its new location. The body immediately starts to heal in the new graft, and since the incision for the follicle is so small (~1mm or less), the healing progresses fairly rapidly, and should be fully healed in their new location by 10 days following your procedure. Typically if a patient colors their hair once every 6 weeks, I advise them to color it 3 weeks before and then 3 weeks after their hair transplant procedure. 21 days is plenty long enough for the wounds to completely heal and is safe to color your hair. Certainly at 2 months it is safe to color your hair.To answer your second question about hair growing back in the donor area following extraction, the short answer is no. The hairs that were removed from the donor area were literally removed and transplanted to the areas of loss in the front. It's in a way like transplanting a tree; if you remove a tree from a given location and move it to another, you don't expect the tree to regrow where it was take from, as it was removed. The FUE procedure removes entire hair follicles from your donor area. A person is born with a finite number of follicles, roughly 100,000, and a hair restoration procedure, whether FUE or FUT only moves around whatever hair is remaining on your scalp. The beauty of the FUE procedure is that the follicles can be moved without using a scalpel, without creating a linear scar, and without using stitches. The surrounding hairs around the FUE sites where they were taken from in the donor area grow to camouflage the tiny circular scars left behind following an FUE procedure. And to clarify, both FUE and FUT leave scars; there is no such thing as a "scarless" hair restoration surgery. Every time you incise through the skin a scar will result. There are no exceptions. Since the hair follicles originate under the skin, the skin must be incised to obtain the hair for transplantation. So with the FUT linear procedure, a linear scar is created. With an FUE procedure, such as one with the ARTAS robotic hair restoration system, a very small, flat, circular scar is left behind in the location in which the follicles were removed.