Here are pictures of Monte (Poseidon) as a puppy, then as an adult. His face is just like Bucky’s, but with his mother’s red hair only slightly darker.
Here are pictures of Gus (Hades) as a puppy and an adult. He is the carbon copy of Bucky. Looking at him I could never guess who his mother is.
Lucy (Artemis), she has a face just like her mom but with her father’s expressions and coloring (apart from her white points). As a puppy she had white on the top of her head as well.