Quoting myself from previous instances of this question:
Blue eyes and blonde hair was an ideal, but German propaganda actually tended to downplay physical features when discussing the ideal Aryan. A Hitler Youth booklet called "Faith and Action" says: "Race means to be able to think in a certain way. He who has courage, loyalty and honor, the mark of the German, has the race that should rule in Germany, even if he does not have the physical characteristics of the “Nordic” race. The unity of the noble soul and a noble body is the goal to which we strive. But we despise those whose noble body carries an ignoble soul."
Hitler's actual definition of 'Aryan' changed based on what was politically convenient. Originally it was "white, non-Jewish" but it became necessary for him to add Slavs to those who were white but not Aryan. The lack of a specific definition allowed him to change it when it was convenient, as was the case in Yugoslavia with the Serbs being considered the "most Aryan" in the region... until a Serbian anti-Nazi coup forced him to declare the Croats the most Aryan.