[Kevin Sevcik]

As noted above. You can attempt to control an opponent's platform. You should beware that they are allowed to pin you indefinitely while you're on the platform and vice versa. And also, if you're sitting on the platform preventing them from getting on it, you run the risk of being on the platform at the end of the round and scoring points for them anyway. The color of a robot on the platform doesn't matter. Thus the "3 or more" phrasing in the rules.