Our two youngest, now 14 & 15 yo, are adopted.
Our son is biracial (white mom, black dad) and he’s been the same cinnamon color since his birth and turns deep brown when tanned.
Our daughter is black. She was so pale (with bright blue eyes) at a few days old that I thought the adoption agency had given me the wrong baby. Over the next year or so her skin tone developed into a light golden brown color. In the summer she tans to a deeper golden color.