According to the Ethiopian Parliament site, Oromia is the largest of the new states. It's difficult to get an idea of this state's geography in relation to the old provinces. The old provinces of Shawa and Arsi should be totally within Oromia, and also at least parts of Sidamo. The connection with Sudan is probably through Gojam.
Reports vary in flag ratio and shape of the tree.
Before colonization, the Oromo nation was free and had their own social, political and legal system. In Gadaa system the Oromo society is grouped according to their age and undertake different responsibilities in different ages. In Gadaa system, the Oromo practiced their own religion by worshipping Waaqa which means God. Waaqa is one and the same for all. In the Gadaa, the three colors black, red and white, represented those yet to enter active life, those in active life and those who had passed through active life, respectively, in short we can say, the past, current, and future.