The Coluan race were a green-skinned humanoids with the average member having a "level 6" intelligence, which was a genius by the standard of Humans. Coluans were pioneers of super advanced technology and had exceptionally long lifespans lasting for centuries, due in part to the race's advancements in genetic manipulation.
Megans were the inhabitants of the planet Mega, known to the natives as Colu. Very few Coluans survived the atomic wars of Colu. One was Professor Hecla, who created the android Brainiac. The majority of Coluans had greenish or blueish-skin, although some had skin tones that were indistinguishable from human skin. This could be due to heavy exposure to radiation caused by the nuclear fallout, which may have been poisonous to some Coluans, causing their skin to change color.