Gabrielle Doe aka Halo is one of the supporting protagonists in Batman: The Brave and the Bold.
She is voiced by Colleen O'Shaughnessey.
Violet Harper was once a criminal sociopath but was murdered by a gang. As fate would have it, Harper was being observed by the Aurakle, an alien composed of rainbow-like energy. Aurakle merged with Harper's body, awoke with amnesia, and was now an otherwise innocent person. Her power is much like a Green Lantern in terms of creating constructs but she can access an aurora of energy of several colors: red for heat, orange for force blasts, yellow for light, green for stasis beam, blue for distortion effect, indigo for tractor beam, and violet for all powers to be used at once.
She chose the new name of Gabrielle Doe and was recruited by Batman to join the Outsiders with the codename of Halo. She later appeared in a mission to stop Kobra from finishing a ritual to bring about an age of chaos.