The game makes no effort to distinguish from zombiefied africans from non-zombified africans, both are presented as "The Other", menacing and dangerous, which plays into the "dark continent" trope you find in so much colonialist literature. It's not like you really ever stop to concern yourself with this, though, since they're constantly trying to kill you and you have to mow them down by the dozens. The only identifiable black character is a ready-for-hollywood light skinned Anglo action chick, "one of the good ones".
To top it off, her unlockable outfit is a leopard skin bikini, with an animal tooth necklace and warpaint. All she would need is a bone through her nose to complete this ensemble.
Nothing racist about all this, nosiree.