Australia is not New England. You won't find vast, native forests turning crimson red. Because most of the native trees (eucalypts) are evergreen, they don't change color; they just shed bark.
Packing for Australian autumn requires layering. autumn months in australia
Australia is famous for its evergreen eucalyptus trees, so you won't see color everywhere. To see the famous golden and red leaves, you need to go where European deciduous trees were planted by settlers, or where native flora changes color. Australia is not New England