Apparently the reason us redheads aren’t known as orangeheads is because the word orange as a color hadn’t yet been invented.
I found this factoid out here: Why Do We Call People With Orange Hair Redheads? | Geekosystem, and the Online Etymology Dictionary backs it up.
Either term, however, is way better than carrot top, considering:
- Even if our hair looks orange, it looks nothing like carrot orange, and
- Carrot tops are green. Carrot bottoms are orange. Yes, I do realize that the top in carrot top references the top of one’s head, but that’s totally not how is sounds.
And calling us gingers is relatively new, maybe as recent as the 19th century. (Source)