I am experiencing discoloration of skin in and around recipient area. (Photos)

I got ht before 4 month and doctor prescribes me minoxidil and finestride feverything is good until my 3 month mark my skin color change in receipent area dramatically and get darker ,my hair growing is good i have no pain no redness .some itching , dead skin came because its winter here and the weather is so cold ..my doctor told me this is normal and will fade but i want to ask u if u doctors did u experience something like this before ..and if not can u tell what is this and how to solve it