There is quite a wide range of skin color in native Africans. I don't think a real determination can be made without DNA testing. I am becoming more and more skeptical that he is actually the spawn of Stanley Ann Dunham.
There are a number of stories with reasons as to the possibility that Stanly Ann was not Obama’s mother. I tend strongly to discount such because of some photos that seem real and that Obama did go back to Hawaii and take care of ‘Toots’(I think that was he called her)who was Stanly Ann’s mother’s burial at sea. Your take as to skin color and my take as to skin color go to my contention that his skin is not in and of itself an identifier of Obama’s heritage.
One of my theories is that Barry was the child of Grandpa Dunham and one of the Indonesian Hookers that worked at the bar Grandpa took Barry to many years later.
The pimp at the bar was always 'interested' to see Barry. (this is from Barry's own book)
She was flown back to Indonesia to have the baby, then Stanley Anne flew there, picked him up and brought him back to her Grandparents in Hawaii. This way the baby was 'in the family' and Stanley was still free to roam the globe.