Colin Baker's portrayal of the title character in Doctor Who was... shall we say... controversial. This new regeneration was unpredictable and egotistic, portentous and eloquent, bombastic and confident. The most striking aspect of his persona was his tasteless, multicoloured and clashing costume. In fact, Colin wanted to dress his Doctor in black, specifically black velvet, to reflect his character's darker personality. It was producer John Nathan-Turner who insisted on his garish apparel. Fans quickly categorised this persona as the 'unlikeable' Doctor...
Colin's era included an 18-month hiatus, announced mid-way through transmission of Colin's first full season. The criticism came straight from the higher echelons of the BBC, attacking the overly violent shows, nonsensical storylines. Colin's next season was reduced in size, 14 episodes in all, and entitled "The Trial of a Time Lord." Apt, as the series itself was "on trial" at this time. Although Colin had his heart set on beating Tom Baker's run of seven years... he was dismissed from the part at the insistence of BBC management, who wanted to make some major changes to the show. He was removed after starring in only eleven televised stories and just short of three years in the part (1984-1986).
The Sixth Doctor has since returned in Big Finish Productions audio plays, and these have been better received. A fan poll in 2001 voted him as the "greatest Doctor" of the audio plays. It's been said that he was not given enough time in the 1980s to 'unpeel the layers' of his character. And the Big Finish covers that have featured an all-blue variation of the costume has become a popular alternative. Ironically, one of the few requirements set down by the designer of the costume Colin wore in his televised stories was that it shouldn't feature any blue at all, as this would interfere with some of the series' special effects.
It's fair to say that Colin didn't hand over the TARDIS keys to Sylvester McCoy - they were taken away from him!