Ed Gein sees green blood in "The Ed Gein Story" (episode four titled "Green") as a representation of his delusional state and rationalization. The green color symbolizes how Gein perceives the blood of Bernice Worden (one of his victims) as poisoned or contaminated. This visual motif is used to reflect his psychosis and twisted belief that killing Bernice would purify her from that supposed poison. The green imagery conveys his detachment from reality and the corrupted nature of his view, which also played a role in his being declared legally insane and unfit for criminal responsibility during his trial.
In summary, Ed Gein seeing green blood reflects his distorted perception and mental illness rather than any literal occurrence. It symbolizes his belief in contaminated blood, his nausea toward blood, and serves as a cinematic device to highlight his loss of grip on reality.
