Wearing a hat is another way of exuding confidence. If you decide to go with one, make sure that it goes perfectly with your outfit. For the color, it does not have to be always a match; rather, it has to be a complement. Just make sure that your outfit's and hat's color, even different, can harmonize together. As for the style, as long as you don't wear a baseball hat to match your gorgeous evening wear, you're fine. lol.