We know budgerigars like a pet but they live in Australia. They known as small parrot in there. This budgerigar documentary may help you to understand your budregigar easily. You can watch it in wild life in their own nature.
Their color is generally green in wild life.
Predators attack to catch them but budgerigars are so fast in wildlife.
That is the lick for budgerigar documentary: https://www.youtube.com/watch?v=PcnrFCTIOAg