If you want to do something really wild, have a look at the crazy colours that are temporary but really bright. In Oz the brand is called Fudge and it comes in a tube. I usually put a bit just as a streak when I am on holidays. I haven't done it last week but I still have 10 or so days left before I have to go back to work.

You only need to use about a teaspoon full for one streak, but I really have no idea about what sort of chemicals they contain.

When I say wild colours, I mean really wild - orange, green, red, raspberry, purple, blue, yellow.. I like the raspberry.

Helen