The flag of the Cook Islands, officially known as the Cook Islands Ensign, is based on the traditional design for former British colonies in the Pacific region. It is a blue ensign containing the Union Jack in the upper left, and on the right, fifteen stars in a ring. The stars stand for the fifteen islands that make up the Cook Islands (Tongareva, Rakahanga, Manihiki, Pukapuka, Nassau, Suwarrow, Palmerston, Aitutaki, Manuae, Takutea, Atiu, Mitiaro, Mauke, Rarotonga and Mangaia).