The ceres on male budgies will only mature to the royal blue colour by the time they reach 6 months old.
From the photos you posted on your introductory thread, it's clear that your budgie is already an adult because it has the fully white irises and already has the adult plumage. The photo you shared on post #8 the cere is clearly very white and this would indicate a female.
We based our opinions from the photos you posted of your budgie back then and from our experience in budgie ownership.
RIP sweet Tito (Summer 2008 - January 17th 2013).
You are missed and never will be forgotten.