Colin Baker portrayed the 5th regeneration of the Doctor. He had some good episodes but sadly he only had eleven episodes. They fired him and replaced him with Sylvester McCoy.
The producers wanted Colin Baker to return for a regeneration scene but he was so pissed off for being fired that he refused. They then had McCoy to wear a wig and the 6th Doctor's clothes. McCoy's face was distorted while regenerating so that people couldn't tell that it was McCoy. But if you watch carefully, you can tell that it's McCoy instead of Baker.
Colin Baker planned to star as the Doctor for eight years but he only got to star in Doctor Who for two years. He had the least amount of stories than any of the other incarnations of the Doctor in the old show.
Colin Baker and Tom Baker were both Doctors and both have the same last name. But Colin is not related to Tom. Colin Baker's incarnation of the Doctor was rude sometimes.
Colin Baker was a good Doctor. He was no Jon Pertwee or Tom Baker but he was still good. I give Colin Baker's Doctor a 4 star rating.

Flamboyant and annoying, but far better than doctors 8-10