Colona is a city in Henry County, Illinois, along the Green River. It is part of the Quad Cities metropolitan area. The population was 5,099 at the 2010 census, down from 5,173 at the 2000 census.The City of Colona was created in 1997 by the merger of the former City of Green Rock and the former Village of Colona. It was the first community in Illinois to merge by popular vote.