Photon is a member of an alien race. He is a silver and blue colored humanoid alien with a green flame coming from the top of his head a trait shared by all members of his race. He was recruited as a member of the government sponsored Youngblood team for their away team, a separate team specializing in missions away from home and subsequent spin off comic book.
Photon recently returned in the new Youngblood team, but has now become a woman. According to Photon, his/her people switch gender every seven years in order to enjoy all aspects of their true selves.