See WB, even Marvel thinks you should always have a Green Lantern on the team. Introduced in Avengers #85 (1971) by Roy Thomas and John Buscema, Joseph Ledger of Earth-S (the home universe of the Squadron Supreme) was an astronaut that encountered and rescued the Skrull, Skymax. Skymax rewarded Ledger by giving him the Power Prism. Joe would use the Prism to become Spectrum and the two would help form the Squadron. He would remain with the team for many years and was the one to convince Hyperion to help the Avengers, who travelled from Prime Earth, to get rid of the Serpent Crown.

When fellow Squadron member Nuke went missing, Joe went in search of him with the aid of Nuke’s brother. They would find him in front of the heroes’ parent grave grieving at the role he played in their death. He would attack Joe and Joe would have no choice but to hold him in a bubble. Nuke tried to escape but suffocated. Joe would fall in love with Foxfire but a battle with Nighthawk’s Redeemer saw his Prism shattering turning his skin chalk white. He witnessed the death of Foxfire by the hands of Mink, which displayed that the Prism powers at transferred to him. The Squadron would be brought to the Prime universe by the Nth Man. They would continue their adventures for a while until they returned to their home universe.

This version of Dr. Spectrum is probably the most renown version of the character. After the Rocket Raccoon wave figure of Hyperion was released, many people began asking for the rest of the Squadron to be made. He would receive a figure as part of a 2-pack with Hyperion.