Would you call Winston a misogynist? Why does he dislike women colleagues in particular?

I would not call Winston a misogynist. Winston has been been conditioned to fear young women. Young women are indoctrinated into the Anti-Sex league and trained to attract men who are weak. Winston, like all party men, must mask or hide their sexual desire. Showing attraction to a party woman would mean certain death or torture. Winston turns his frustrations into violent fantasies. These fantasies are what he uses to undermine the party in his own head.