Is my Parakeet a male or female

by Andrea
(Sapulpa, Ok, USA)

Tweety

Tweety

Tweety
Tweety

I have 2 parakeets one is a blue parakeet and is clearly a male because the cere is a brilliant blue. The other one is a rare parakeet and the cere is a pinkish/white color. Is it a male or female. I am wondering because I was thinking about introducing a nesting box but if it is another male then I need to get a female.