You cannot sincerely determine who is "Aryan" in a scientific way because they, the Nazis, already determined who is and who isn't one, and as you are a Slav, you definitely aren't, not according to their rulebook.
An ethnic Germanic and Nord can have dark hair and dark eyes but still be an Aryan, because of who he is. While an ethnic Slav or Jew can have light hair and light eyes, but not be an Aryan, because of who he is.
This also isn't up for debate because this is how they genuinely perceived racial groups at that time as well as their own. Anything deviating from that is a branch from the source, a difference in a opinion that does not align with the originator of this concept.