There are several colours available and that's how it looks like:
How awesome is that?!?!
You just use them like a topcoat and after 30 seconds the pattern appears. The more colour you apply, the larger the crack patterns will be, but you have to be super quick, the dry crazy fast.
I bought the black one and tried them immediately, I know the polish is applied messy, but I was out of time and it's better than nothing:
They dry to a matte finish, but with a topcoat everything is shiny. :-) The graffiti polish soaks up the colour a little bit, on the third pic you can see that, I used two coats and that was the result, I would recommend three coats for a vibrant result. You can use any normal polish as a base and a normal topcoat, so don't let the ad foul you.. *g*