:::Never mind, these countries all have their independence now, and so one is free to visit them and see the earthly paradises they have since become. 

 ::: ... that's if you are feeling lucky and have good Life and Health insurance. Many are not the happiest of paces to visit, e.g., Burma, Zimbabwe, etc. 

 ::: ... come to think of it, since independence many of their citizens have made great haste in moving to the UK, at least the ones who were lucky enough to be able to - until quite recently all Empire subjects had the right to abode here. It's called 'voting with one's feet'. The rest just have to put up with things. 

 :::BTW, you need considerable organisation and resources to commit 'genocide' and at no time did the British have the personnel or time to spare to do any such thing, even if they had wanted to, which they didn't. Britain ran the whole of India with less than 20,000 people, and India had by far the greatest British presence inside the country compared to the other colonies, protectorates,, etc. 

 :::Besides, you need a considerable proportion of any 'native' population behind you to commit 'genocide', usually on other local people they are unfriendly with. 

 ::: .. .and you don't attempt germ warfare against someone using Smallpox unless all your friends and allies are safely vaccinated against catching it themselves. And as Edward Jenner had only comparatively recently discovered the technique it is highly unlikely that the whole white population of Canada had received them. Smallpox is virulent and nasty, and only a fool would attempt such a thing without protecting his own people first. You see, the people trying to distribute the virus would get it themselves, and then spread it everywhere they went. To anyone. I'll leave you to decide how likely to be true that little 1862-63 'factoid' mentioned above is.