How to dip a razer hydra finger in paint to draw?

I have yet to find a good answer to a needed function for my future project. I wish to create a method of writing with a razor hydra controller finger with different paints cups, offering a form of fingerprinting… either thru vertex painting, pixel changing of the texture or even particle clinging of some sort… is there a way to do this effectively? Just want dip a finger in a cup of paint and draw with it for a limited time…. any ideas people?