(For those of you wondering: Yes, that's a lemon.)
It's not exactly a translation mistake, rather a running joke left over from the communist era from a movie called The Witness. The movie is a satire, guess what, about the communist system. And to a smaller extent still applies to politics in general. Go figure.
(For those of you slow on history, no, Hungary is not a communist country anymore.)
At some point in the movie, the leader of the Hungarian Orange Research Institute, tasked with the creation and cultivation of Hungarian oranges (so we don't rely on import), has to present the year's first orange harvest to Comrade Bástya, supreme military leader. Unfortunately his children ate the only orange that the orchard managed to produce (no, Hungary does not have the ideal climate to produce oranges that are not sour enough to make your butt clench up). Scrambling to avoid admitting failure in the last minute they present a lemon instead. When the leader tastes the lemon and demands to know what the hell it is, they answer:
"This is the new Hungarian orange! A little bit yellow, a little bit sour, but it is ours!"
This is only one of the many lines that became iconinc from the movie, and is still used to describe failures that are dressed up as successes for political gain.
(Hungarian Orange is currently the title of a newspaper that writes about culture, politics, economy, and other serious topics. It used to be the newspaper of the young democrats' party. Go figure.)