Ah, right, I actually had known about that before, but I must have forgotten! It would be interesting to see if there weren't as much controversy around depicting Muhammed whether the common versions today would be accurate; depicting Jesus isn't discouraged at all in Christianity, but centuries of Europeans depicting him looking like them have established a common trope of a white, fair-haired Jesus, which would not have been at all what he actually looked like given where and when he was from. Given that Islam has been much more continuously practiced in the region where Muhammed lived, I imagine that depictions of him probably wouldn't have been as egregiously inaccurate in terms of race, although it's possible other sorts of cultural expectations might have been adopted over the years.
Accurate depictions of Muhammed[0] are difficult to come by.
[0] https://en.wikipedia.org/wiki/Depictions_of_Muhammad