You certainly would be able to feed him pinkies, but it's more a question of whether you should or not.
Most believe that digesting animal protein is hard on chameleons, and that they can get things like gout from excessive protein. So one every long while won't hurt but too many will. And there aren't very many benefits of feeding pinkies, since they don't provide a lot of calcium. They are mostly fat, so they're just a fatty treat more than anything and are not really substantially nutritious.
Beautiful panther in your avatar, by the way. Stunning blue!