How did children address their parents in colonial times?

With respect and as a superior to the child - - children were expected to use formal terms with their parents and all adults.

The colonial relationship between parents and children was similar to the master-slave relationship. Children were expected to obey and serve their parents with complete respect. The idea of children being "seen not heard" is rooted in colonial thinking. Children owed their parents for their shelter and protection and paid for that debt through their labor until adulthood.

the way that they address their parents in colonial times was : They addressed them as Mother, Father, Mister, or Madame. Actually, not only their parents, but the older people in general. Back then, calling someone that is older than you solely by their name was considered rude and unpolite, so people usually use that title as simple form of respect