Ceylon was a part of the British Empire.
I will let you into a little secret that even most Brits don't know.
Britain didn't 'Conquer' very much, we 'acquired in a fit of absent mindedness' the majority of the Empire.
India was not 'Conquered' by the British in the sense we didn't fight the Indian population, we fought the 'French' who by Tradition had to lose lol, we also fought the Moghuls, but they were corrupt and outdated so it was a one sided affair, Ceylon was acquired more by osmosis than by Conquest, they needed administering, so we walked in and administered.
India was famously run by 100,000 unarmed civil servants, we had an army there of about the same size, 100K but the main force was 1 million armed Sepoys (local Indians) who were much better at running the locals because they were locals.
Ceylon was always run as a separate colony.
Canada was not Conquered by the British, it was the French did that we just relieved the French of it, because they were not as good at 'Empire' as the British, who learnt our lesson over the American colonies.
Most of Africa was acquired fighting the slave trade, we couldn't be ar5ed running these Countries until it became obvious we had to make our presence felt, to stop the wretched Slave Trade.
In the superb Michael Caine film 'Zulu' which is about how a couple of hundred soldiers defended an out post in Africa from 4,000 Zulus, what is never mentioned is why we were there in the first place, which was to stop Slaving, the joke is that Chief Bhutilazi who is depicted as the Chief at the time of the Battle has had the cheek to say Britain owes money to the Zulu for slaving, when it is us who stopped it, when the Blacks wanted to continue?
We also acquired Egypt at one time for the Suez Canal, actually we only acquired it because the French showed an interest in Buying it, we beat them again, Well its Traditional lol.