Morgan Blue was a colonel in the Combined Galactic Resistance which fought against the Daleks. He was also the uncle of Journey and Kai Blue.
When the Twelfth Doctor arrived on the Aristotle (the ship under Colonel Blue's command), Blue wanted to kill him in case he was a Dalek spy. However, Journey stopped him and convinced him that they were in need of a physician, mistaking the Doctor for a medical practitioner.
It was under Colonel Blue's orders that the Doctor, Clara, Journey, Gretchen Carlisle and Ross were shrunk to undertake an expedition inside of Rusty and determine what made him turn good. When "Rusty" was fixed by the team inside, he sent a distress signal to his Dalek fleet and the colonel led a group of resistance fighters in defence of the Aristotle. He was one of the few soldiers to survive the attack. (TV: Into the Dalek)
