You need to look up words in the dictionary and read some history.
British colonists are, by definition, immigrants and invaders, hence why they're migrated from across the Atlantic here to colonize the land they were invading.
Immigrants are immigrants, despite what an obnoxious prat ranted on the new fangled Tweeter thingy at 5am.
Further, people migrating to land that was theirs hundreds, if not thousands, of years before it got invaded by British colonists and their descendents are not exactly invaders.