what is happening- is your budgie is maturing. All budgies are born with the same coloured cere which is a light whitish-pinkish-blue colour.
When budgies mature their cere changes colours depending on their sex. Female budgies have brown and male budgies have a darker blue.
So.. this just means that Fry is a girl ^_^ so theres nothing to worry about!
You might want to take a look at this page:
About Budgies