If you look at there two nose wholes the one that is a darker shade of blue is a male if it is a beige/white it is a female
 

 It is very
difficult to tell male or female parakeet. But there are few differences which
can be identified by the expert only. The proper way of sex differentiation is
by blood test. Following are differences in adult parakeets.

1.     
The female have white or pink nose, and cere is brown
or pink cere.

2.     
The male has blue cere.

3.     
According to Darwin,
during breeding season all male birds have very bright colors.