Technicolor was born on a strange planet with horrifying creatures called humans (hew-Manz). She lead an unhappy life there. She then met someone special called the doctor. They traveled through all of time and space together. They started to fall in love. But one day, she fell into a pit of radioactive waste, only enabling her to be animals. Broke hearted, the two still loved each other, but were too shy to say it. One fateful day, when faced against Daleks, the two were forced to jump into a wormhole. While in it, they got separated, and landed in different areas of Equestria. Since wormholes are dangerous, each thought the oter was dead. Technicolor landed in Ponyville and ended up being taken in by Rainbow Dash, until she got her own place. She discovered she no longer change species, but pony breeds, and could now change colors and light up. She befriended the Mane 6, but still missed the Doctor. She became an Arial Performer. He still fixed things in Equestria. Both looked for the other. The Doctor was amazed by Techncolor's flight skills, and Technicolor fascinated with the handsome stallion around town. One day, the Doctor saw Techni at a cafe, and tried to ask where she came from. When she refused, he told her his story, causing them to recognize each other. They fell in love and such. The end.
(In some RPs I set it before I find the doctor)