Color can be all over the place on wines of this era and one color is not better than another. Some will be like a rose, some darker, some in the middle. The one thing that is generally bad is BROWN!
But are the darker colors due to some other wine (like Barbera) being mixed in, or can pure Nebbiolo be that way?
I would assume so, my thoughts are yes…but it’s all just a guess at this point. Maybe when I’ve had a few cases of wines that are sound and from the 60’s & 70’s I’ll feel more comfortable shifting from a guess to a statement.
Rotofermentors can give a darker color. A few places started to use them in the 80’s I believe.