Best method to track multiple objects?

Hi everyone, I realize this questions is a pretty broad one but I was wondering what in your opinion is the best method to track multiple objects simulteaneously? My goal is to track 12 Objects independently of eachother and translate their positions into X/Y coordinates. I've been trying to do HSV matching with Camshift, but I realize that with a limited number of colours to choose from I might not be able to reach my 12 Object goal... Any guidance would be greatly appreciated!! Cheers, Chad