Slavery. Yes, the British Empire was one of the chief agents in the Trans-Atlantic slave trade. It was also the frist to ban it, and the Royal Navy kept up substantial anti-slavery patrols to intercept slave ships.
Religion: The British Empire allowed missionaries to operatere freely. Please not how sucessful they have been in many places, such as India, Pakistan, Afganistan, Burma, Eygpt etc. The Spanish and Portugese, in South America rounded up the natives and forced them into communal farms come convents. Result, South aamerica is full of catholics, and the former British Epire mainly has the religion it started with.
I never said the British Empire was a harmless game run by a bunch of Saints, just that it was less bad than others. If you can't accept that, please remove your head from your arse, and try again!