blue with the flag of the UK in the upper hoist-side quadrant and a large seven-pointed star in the lower hoist-side quadrant known as the Commonwealth or Federation Star, representing the federation of the colonies of Australia in 1901
the star depicts one point for each of the six original states and one representing all of Australia's internal and external territories
on the fly half is a representation of the Southern Cross constellation in white with one small, five-pointed star and four larger, seven-pointed stars