So if Marcus is really the song of Nick Fury, why doesnt he look mixed? Such a simple gripe but it's something that nags me every time I see him in an issue.

My friend's father is Chinese and his mother was Indian, though the mother had dark skin and the father had very light skin color he still looked completely Chinese. As if he never gained any features from a physical aesthetic standpoint from his mother. Things like that happen.

Arent the genes of the father stronger than the mother when it comes to pregnancy? So that case sounds reasonable.

Parental genes are divided equally gender doesn't really matter since both males and females have dominant and recessive genes. An example would be Blake Griffin. The only part of him that gives you insight on him being a bi-racial guy would be his curly hair. But in his family it's his father who is Black and not his mother. The same could be said of Michael Jackson and his kids.

Jeez so he inherited nothing from his pop

There are other things you can inherit from your parents other than physical appearance. Internal things, like in his scenario the infinity formula in his DNA. Other possible things would be their moods. The thing is these genes make proteins that interact with each other and with chemicals in your body. This then could account for eye pigmentation or even something more subtle like the amount of mood altering hormones they have.