Happy to be corrected on this, as I'm not Middle-Eastern, and I don't claim to be an expert - but as I understand it, the "Iranian" ethnicity is kind of a tricky one as far as its classification.
Officially speaking, Middle Eastern / North African (MENA) people are considered "white" by the US government census. But as I'm sure we all know, MENA people have become increasingly subject racially-motivated bias, especially since 9/11. And that bias is often perpetuated through profiling physical features, which would arguably classify it as a "race," culturally speaking.
Where it gets tricky is that many people living in this countries -- and who have emigrated to the US or other countries -- have lighter skin, and might be white-passing. So if an ethnicity is not classified as a race, but some people within that ethnicity experience racism based on their features, but not everyone within that ethnicity exhibits those features -- it's complicated.
Also - I'm not 100% sure about this, but isn't there a somewhat higher population of light-skinned, "white-passing" people in Iran, compared to other MENA countries? I feel like I've heard that to be the case, and I've observed it anecdotally among some of the Iranian-American people I know, and the artists of Iranian decent I've been exposed to (Karimloo included). But I don't want to make sweeping generalizations about a country I've never been to, so I won't say that with any confidence. It could be that what I'm witnessing is the colorism at play in media.
In either case, I'm sure there's a diversity of skin tones like in most countries.