Budgie Cere Has Turned Brown And Flaky

Hi guys,

I'm needing some help with my little bug Stormy. He had a lovely pink cere when we first got him but now it seems to be brown and flaky. He is still active and eating.
We got him as a 'baby' budgie unsure how old he actually is and he's been with us for one year.

Hoping someone might be able to shed a little light on this.

Thanks