Some babies may have increased pigmentation because of exposure to maternal hormones in the womb. This increased pigmentation does not persist. The high red blood cell count in newborns makes them appear much redder than older babies. This may also make the baby appear darker. All of these are moot points when it comes to the race of the child.
Some black babies are quite light skinned when they are born but become darker during infancy.
Some Caucasians have darker skin than some blacks. All of this misses the point that an interracial child is neither more black nor more white based on his appearance. This is all an issue that depends more on societal attitudes and the parents' attitudes than it does on genetics or skin color. I very seldom see him without a shirt and was shocked at the size of this lump. He has had no injury, there is no redness, or pain except for the immediate areola area.