I think it's a shortcoming of the way the clothing is being attached to the character. What I think is happening is when you generate the sovereign (or unit), if you pick the hooded piece of clothing it overwrites the hairstyle because both the hood and the hair they both use the same hook (head).

    The way kids generation seem to be handled is that they randomly pull their outfits/hairstyles/headmodels/skintextures from the selection available to parents' races. Incidentally, I noticed that girls favor mother's and boys favor father's. Coloring, however seems to come from either parent randomly.

    Point is, if hooded clothing is available during the mother's/father's race selection, chances are some of your kids will end up bald . It's not the worst case scenario, believe me! I had a game where two of my sovereign's children used aged complexion, beard and mother's coloring (silver hair). They looked like grandparents.