Unlike their female relay runners kissing on the mouth, these rainbow-painted Russian Army tanks are just a happy mistake. Sadly, almost nobody—especially the military—is celebrating the gay cause in a fascist country that is actively prosecuting LGBT people.
The Russian Army painted a set of tanks rainbow recently for an army drill in Moscow. Clearly, there's some confusion going on here.
Truthfully, this special paint scheme was solely for a biathlon exercise (which the US will be participating in next year), and not an open protest like others. Still, somebody in the Russian military must have made the connection.