Colleen was indeed first turned into a given name in the USA and Australia. It was not used as a name in
Ireland until famous American actresses named
Colleen (Dewhurst, for example) somewhat legitimized it in
Ireland, and it got a bit of use there in the 1980s (but was never popular).
I have a friend who was born in the USA around 1950 named
Colleen. Her paternal grandmother was born in
Ireland, and she has told me that the grandmother was very upset at her son for naming his daughter
Colleen. She says it was years before the grandmother stopped asking her son "When are you going to give the colleen a real name?" :)