breeding and sexing

Question
i have 2 budgies n i dnt now whos a girl n whos a boy. i have a small yellow and a slightly biger white and blue one. i think the yellow is a female because around its nostrold is a brownish goldish colour. the yellow seems afraid of the other beacuse whenever the white one goes next to he/she the yellow flys somewhere else but at the same time they feed eachother and i dont now if they are going to breed or if i should seperate them beacuse the white seems to annoy the yellow one.

Answer
Brownish ceres are a female trait, but females tend to be the dominant bird.  Feeding each other is very common in bonded pairs, so the white one is probably a male.  If you want them to breed, leave them together.  If you don't separation is probably a good idea.  I wouldn't worry about them annoying each other.  This is common with breeding.  Sometimes males will be very persistent and the female will often get frustrated.  As long as they don't get violent, it should be fine.