Shoot, I was hoping there was like a contact lens or a pair of glasses or something. I am not into illegal gimmick or things that have a good chance of messing me up.
Do you meaning going from Hulk to Avatar? lolYeah, like wearing a hoodie walk up to some one. They will think you are the opposite skin color than you are. Then you do some stuff and BAM you are now a different skin color. And you can take off your jacket and what not.
I would say that it doesn't currently exist. I hesitate to discourage anyone from finding supposedly impossible methods.
That's what magicians do - impossible things. I just have no way to safely suggest any possible methods.
It's not revealing if the trick doesn't exist yet.
There was a trick on the market years ago called Tattoo Joe, where you could make a tattoo "appear" on your arm. I wasn't too keen on it from the videos but you might want to look into that.