Red Dalek (Susan and the Daleks)

One Red Dalek was present in the occupied London during the 2150s Dalek invasion of Earth.

Patrolling Trafalgar Square with a Silver Dalek drone, the Red Dalek noticed an unauthorised humanoid on a bench — Susan Foreman, who had unwittingly gone back to the middle of the invasion in the Doctor's TARDIS. She fled up a flight of stairs and took refuge in said TARDIS; the Red Dalek attempted to follow her up by hoverbout, but was too late to stop her escaping. However, it ordered that the Blue Chrono-Dalek give chase to the intruder. (TV: Susan and the Daleks)

Behind the scenes
The idea of a Red Dalek being involved in the 22nd century Dalek invasion of Earth was actually introduced by Daleks' Invasion Earth 2150 A.D., the cinematic retelling of The Dalek Invasion of Earth starring Peter Cushing's Doctor. This Red Dalek had a different design in line with the default Daleks used by the two Peter Cushing Doctor Who movies, however, while the Red Dalek used in Susan and the Daleks closely matches a 1960s television Silver Dalek with a change of colour scheme. The Red Dalek Leader was depicted similarly on the cover of The Mutation of Time.