You could take white folks and turn Slavs in to Aryans by adoption when young or "honorary" and similar maneuvers. No way, no how would the Nazis treat Africans well, Ethiopians or any other ones. While there were certain aspects of the Muslims/Arabs had admired, and also a Karl May view of Native Americans, and the Japanese were "honorary Aryans" the reality was that non-whites could be officially tolerated if need be, but were Untermenschen. Change this and you turn Nazi philosophy and ideology upside down.
If anything, the Nazis were very inconsistent regarding racial polices and routinely modified their ideaology to suit the situation. For example, the initial ideaology was that only Germans, Dutch and Nordics could ever possibly be "aryans".
Then, through the pre war and war period, Japanese, French, Spaniards, Croats, some Indians (well, the pro German ones), pro German eastern Slavs, pro German Arabs, pro German Greeks etc. were all granted either full aryan or honorary aryan status.
In short, for the Nazis, "aryan" status depended their needs at the moment and included the idea that aryans / aryanism were both an ethnic group and a mystical state of mind that existed in all warrior groups. Thus pro German cossacks, were honorary aryans.
In a German victory, my bet is that the Germans would have no trouble declaring after uhmmm..... "
exhausting historical research" that say, select groups of Tanzanians and Togolese (both former colonies and potential allies) had "aryan states of mind" and were thus qualified to be honorary aryans. Ditto for Zulus.