It's most probably a boy. Most people assume if the cere is pink it's a girl, and if it's blue it's a boy. That's not exactly the case. A girl budgie will have a lighter cere, like a light pink, white, or even a shade of light brown. Boy budgies have darker vibrant colors, anywhere between dark pink or magenta, to purple, to blue.

The best way to determine the gender is after they are around 6 months old and fully developed. In my case my baby budgie's light pink cere turned to dark blue after a few months. But if the colors are already vibrant, it's easy to tell.

Budgies less than 4 months old have bars running from the back of the head to the cere. Their eyes are completely black unless they are luntino or albino). The cere is pink, purple for the males and pink with white circles on the cere or white cere. Has your bird had its first moult? If not then it's under 4 months of age. Around 6/7 months the cere will turn to a chocolate brown colour for females. Males will go from their pink cere to a purple cere after their fist moult. .

I got it a month ago, and I checked and it was a light blue (It's very young, I got it at the pet store) and I assumed it was a boy, Just today I found that it had a mix of blue, purple and pink on his cere. Can anyone tell me what gender my budgie is? Thanks!