Heinlein:Robert:Time Enough for Love:50:Redheaded of course... (Brian Hicks)

From the Quicksilver Metaweb.

Here Lazarus Long mentions that all "natural long-lifers" have red hair, and gives the Wandering Jew as an example. Presumably he would not be referring to the general population of the Howard Families, but people closer to himself in longetivity, say at least 250 to 300 years natural lifespan. It's implied by Lazarus that he's met other unmentioned natural long-lifers, but they may simply be his descendants.

For readers of Quicksilver it may be interesting to note Enoch Root's hair color.