Like in my profile picture. Is something wrong with it?

He probably just went through a molt. Sometimes colors change after their first molt.

How old is the budgie?
We used to have a budgie, when she was young she was blue with a green tint, then when she matured she became green with a tiny hint of blue. Then when she was a lot older (we think she might have gone through some sort of budgie 'menopause') she went blue again.
If your budgie is very young or reeealy old, it might just be related to his hormones.