Question

What are colons? Where are they found? And why were they called colons?

Answer 1

you have to understand colonies
If I say India was a colony
so it was the colonies of bristish people who are living in India during colonial period

so we can say that the people living in a colonies in other country and subjected to there motherland are called collons

the French people living in Vietnam during collonial period are called colon .

hope you get it

Answer 2

Colons were the French citizen living in Vietnam.

they were found in Vietnam.

They began delivering that they might lose their jobs as teachers, shopkeepers, policeman, etc to educated Vietnamese.

hope it helps
thanks..