I've had Stormie for a little over a year now and his cere is still purple, it's not like a light purple but it isn't a deep shade either, I've been wanting to know his gender for a while now. He definitely acts like a male, but I did have a female in the cage with him his whole life but she does recently so I don't know if that would affect his behavior because I know some birds will take the role of a male if there are 2 females or something like that lol. He is white, with some black markings in his back, sky blue patches on his stomach and chest, sapphire blue patch on his butt/ where his tail begins, and his tail in gray with a white stripe down the middle, like lightning, hence the name Stormie lol if that helps.
Welcome to the forum! I see this is your first post.
We often hear you can sex budgies based on their behaviour, but this is not a reliable way to sex them. Many budgies exhibit behaviours of the other sex so relying on behaviour often leads to "mis-sexing" (I just made that word up. ) My budgie Gracie would probably have been called a boy based on behaviour alone as she head bobs and sings quite a storm.
If the cere colour is even, based on what you said about the purple colour, I'm going to go with male. Posting a picture would be icing on the cake to help confirm this.