Traditionaly Yolŋu paint their yiḏaki with ochers.
These ochers are not easy to get everywhere and you often only need a small amount.
As a service I now offer 4 10cc cups with the 'Yolŋu colours'.
Black
Yellow
Red
White
1 cup is enough to paint a large piece of your yiḏaki and make it look tip-top again.
Carefully mix some wood glue with water. So that your 'paint' gets the right thickness. Then mix some ochres with the diluted wood glue until a nice consistent 'paint'. Add some more glue or ochres as needed.
I advise to choose a wood glue that is waterproof.
This way your 'paint' is reasonably resistant to moisture. Of course you could also use a different paint carrier.But I have had good results with wood glue D3 from Bison.
Note: these colors don't come from Arnhemland.