For the past few months I have observed that my baby's skin has turned darker from a few areas(face,hands, legs, knees)which are exposed to the sun, even darker than me(I'm also dusky but he is now 2 shades darker than me) except bumpy area. I have been using sebamed products for him and extra Virgin coconut oil for maalish. I want to know if this is due to the products we are using or something else and what should I do?