That's an interesting but extremly spesific question which would probably hard to answer. I would say that ginger people wouldn't have accepted in the Nazi idea of races, for the fact that red hair is very common in jewish families. Also consider that as far as I know, ginger people are descended from Picts (The natives of Scotland) and Britain was the enemy of Nazi Germany.

I found an article in the Nazi Newspaper "Der Stürmer" from August 1932 with the title "Ein Jude schändet eine Deutsche in aller Öffentlichkeit" - "A Jew defiles a German girl in public". The article is about the son of a local jew in Paderborn, who was know for harrasing children.

It uses the phrase "[...]der Viehjude Rüben Mintus [...]. Er besitzt zwei Sprößlinge, feuerrote Judenbuben." - "[...]the >Viehjude< (means a jew who owns animals for a living as rancher and is very insulting) Rüben Mintus[...]. Who is father of two fire red Jewboys."

A few sentences later we have "Der rothaarige Judenbube[...]" - "The readhaired jewboy[...]", it might seem like nothing but the Nazi propaganda is full of associations especially while talking about jews, "greedy as a jew", "lazy as a jew", "jews don't work, they let others work", and stuff like that - wich you can find in the same article, too. So you can say that the red hair was probably identified with Judaism, too. Hope that might help you.

Source: DER STÜRMER Here is the article. If you are able to understand German, be carefull, because stuff like this is pure propaganda and has nearly nothing to do with real events, it's purpose was to spread hate wich worked well back then.