When dressing like a clown, it's all about going over the top. Everything is either far larger or smaller than what you normally would wear, in order to emphasize the goofiness of the attire. That is why, if you are looking for clown hats, you are going to find these hats are either incredibly bright, over the top in size, or just have different features that you normally would not wear while out on your own.
It all comes down to the kind of clown hats you are looking for in order to complete your look. There are miniature derby hats that are going to clip onto your hair. These derbies come in all sorts of different colors, as to not only draw attention to the small look of the hat, but to allow you to customize it for your needs. Of course, there are also newsboy-like hats, and although these hats are bright, rainbow hats with sequins and other elements that are all going to look flashy and appear differently when viewed in light. It really doesn't matter the color you want, as these hats have an array of options, and many have just about every other color you can think of, directly incorporated into the single hat.