Your bird is a light green opaline dominant pied. Probably under 3 months old. The light bars are because of the opaline part of the mutation (they may disappear after the moult). I'm not sure of the sex because some of your pictures look like they may have been taken with a flash but the blue bird looks female and the green looks male
He is male, at least thats what everyone has told me. He doesn't have any white on his cere at all though. Here is the thread on the boy that was started before, I have some close ups of him there https://talkbudgies.com/showthread.php?t=32554
I thought girls cere's where brown/tan. Her's is very tan, no color at all in it. I think it was the flash that makes hers look different but in person it is a brown tan color.
Now I am off to read info on here mutation as I don't know anything about it. Thank You for the info I appreciate it.