Doctor Manhattan's body is humanoid, and his build is tall and muscular. His height and relative size vary depending on his needs but generally remain above 1.83 m (6.0 ft) tall. He is completely blue (altering his shade and luminosity at will) and has no hair. On his forehead, he has etched a stylized image of a hydrogen atom. He did this during preparations by the military for his unveiling to the general public. They presented him with a hat as a part of his uniform that had a group of crossed ellipses on it, intended to look like an atom but Jon did not see the resemblance. He replaced it with a symbol of his own, saying that if he were to have a symbol it should at least be one that he respects.