I've heard the blue spectrum turning more females as well, but what I heard was that red spectrums can turn a female into a hermie/male due to light stress. Which I think is believable.
temperature has more to do with getting more or less female ratio than light spectrum. light spectrum has nothing to do with hermies that is in the plants genetics, light stress is not something that exists in a way to herm a plant unless it is burning or bleaching. a major nute imbalance will herm you up real quick not light spectrum though.
I've heard the blue spectrum turning more females as well, but what I heard was that red spectrums can turn a female into a hermie/male due to light stress. Which I think is believable.