I'm one of the lucky one's, I am naturally blessed with white straight beautiful teeth. They are a natural white color because I have always brushed & flossed daily since childhood. I also do not smoke so that helps. People often ask me if I have had braces or if I am wearing dentures, I am always indignant about that!
But weird as it sounds, I have always wished my teeth were a little more crooked, I think there is nothing wrong with crooked teeth as long as they are kept clean.