Hitler invented the word aryan from Iranian and viewed Iran as the Aryan homeland. How did Iran come to be considered "brown" today, especially if they are racially Caucasians and have historically differentiated themselves from the darker arabic peoples near them?

by MuskyElongatedRocket
itsallfolklore

Just to clarify a point: Hitler did not invent the term "Aryan", which was in use by roughly 1600, becoming popular in the early nineteenth centuy. It was then replaced by by most linguists by Indo-Germanic and then Indo-European by the early twentieth century. Hitler exploited the term, but he did not invent it.

I will leave the core of your question to others.