In Australia, state colours are frequently part of a state or territory's set of state symbols.
Some states have formally adopted a set of colours as their official "state colours" while others have de facto state colours that have become well-known through popular use. State colours often appear on a variety of different media, from the state's flag to the colours used in sports. In particular the Sheffield Shield team caps popularised the usage of single colours to represent each state.
References
Australian state colours Wikipedia(Text) CC BY-SA