I think blue might be the exception for colored tinting...I like it! Fairly subtle actually, make people do a double take. And if you like it, more power too you.

 

I've actually seen some of the newer Mercedes-Benz vehicles come with light blue window tint from the factory. As far as I know, it's legal in California.
But you might want to consider if it would bother you (or even make you dizzy) seeing a blue world whenever you look out from inside your car...

 

In Vegas, damn near anything is legal, except blue.