The second one you posted, the purple, looks like a young VT male to me. The rest look female, though I'm on the fence about the last red you posted. I'm apparently horrible at sexing bettas though so I hope more experienced people chime in.
The light colored ones would be easy enough to sex, just cup them and shine a bright light from behind them. If you see a triangular mass behind their stomach area, those are their ovaries and they're female and if not, male. You might be able to see this on the darker bodied ones as well, I'm not sure.