I need help sexing my Turquoisines, please....

[Harpytacines]

I was told the yellow was the female and the mixed colour ones the male, but behavior wise, the mixed colour one seems to behave like female, very screechy like my previous one but yellow...what do you think?

 

[Rozalka]

Pics would be needed but I'm not sure if even then we will be able to help because I'm not sure if we have any active turquoise parakeet owner (I can try to help but I can't promise because of no experience)