Does my Cockatiel beak look good?

I've been reading and saw some say their beak should be one color if he is healthy, but 3 days ago, i bought a 7 month old male Cockatiel and his beak has some discoloration, today he just started to stay on my hand, he doesnt sing much on his own, sometimes he does when he listens other birds outside the house, how do i know if he is healthy?

I can't upload the pics idk why, here are the links.

http://image.prntscr.com/image/680824de30af450d8e8...

http://image.prntscr.com/image/a49c08c66b944c0987a...