Metal Mouth Message Board

I just got my braces off yesterday and noticed my front teeth seem dark about midway down. I'm really hoping that these Crest Premium white strips will get rid of it. Also, there are two little white lines on the bottom of one of my front teeth. It's not leaching from plaque formation, but it almost looks like a crack. Any suggestions on how to cover up, brighten, or get rid of this?
thanks