Ah, problem with the hair going grey at a certain age.
Hm, not sure why that would pop up. It does have a defined age, any hair stuff mods etc?

Got a couple cosmetic hair mods, could those be causing the issue? A couple of them are pretty old, updated by new maintainers, so I wouldn't be that surprised.

Is it safe to delete that line from the defs to clear the error?

I remember adding the defined age for a reason. Not sure, but the latest alien race framework might have thrown out some error without, but can't remember if it was any serious problem, sorry.
Well if you feeling up for it, you can always just delete the line and see what happens. Xd

I'll try that, and see what happens!