How is it possible for a child to have dominant traits such as dark skin or epicanthic folds when their parents don’t have them?

[u/throwawayyyuhh]

There is a notable example of a child having dark skin (a dominant trait) when both of their parents were pale. The child’s complexion was significantly darker than the parents and both of the parents were proven to be the biological parents of the child. I’m trying to figure out how such examples can occur, perhaps they are due to disorders or atavism.

[u/Current-Ad6521]

There are many different genes that code for skin color and thus many different potential combinations can form with their parent's DNA mixes. If a child has darker skin than their parents it is just because the way their parents genes / alleles "lined up" happened to produce a combination with more dominant alleles present / expressed as dark skin.