Blue hair colors, why not? They are very popular among the emo girls and if you want something different then a pink hair color you should definitely try a blue color, celebrity Katy Perry is fan of these alternative hairstyles, you will surely like to have a nontraditional hairstyle. Such bold and intense color is more suitable for hair highlighting but there are many examples of block colored blue hair that you can find.
If you are Blonde or light brown, you can use a semi-permanent blue color. The semi-permanent color allows you to have your own color back in no time. The Blue color will last a couple of weeks or even shorter and you will be able to change it without using another color.