They use them for doing art and body painting for ceremony. In the olden days they only used red, white, yellow and black for bark paintings and painting didjeridoos.
Some people sell their paintings with good designs, and some of the people sell didjeridoos.
For ceremony they use different designs on their body, because there are three different dance groups. Now people do their paintings on canvas, with lots of colors, including green, blue, yellow, red, black and white. Most of the people still use the traditional colours of red, white, yellow and black.