The extra fourth and fifth gel would have to be portal colors that they haven't made Gels from yet. The Co-op portal colors are purple and red. That fits. The fact that I thought there should be a new portal gun with new colors, too, meant there would have to be four new Gels in all. Electrocution Gel would be red and thick, and would electrocute anything that touches it. Adhesion Gel would be purple and thick, and make objects stick to walls. The two new portal/ gel colors would be green and pink. Contamination Gel would be green and thin, and would basically be a liquid neurotoxin. Dizzification Gel would be pink and thin, and make anything you place on it spin around. The new portal gun itself would have the white parts turned into a camo pattern, and black would be a dim, faded shade of pink that illuminated whenever a portal was shot. It would be the long range portal device, and could portal bump on any surface.