This was a science fiction series some years back. It told the story of a group of aliens that had landed on Earth. They had been bred to be slaves to some other unknown race. The main theme of the series is prejudice. The aliens enter into American society, most of them in Los Angeles, and encounter extreme prejudice.
The series also shows how their culture is affected by human culture, not always for the better.
The two main characters, policemen, are Matt, who is a human, and George, who is an alien. They themselves have to deal with prejudice against each other (at least at the first). Things get really complicated when Matt falls for Cathy, who is an alien female. That leads to some serious, and some very funny, things happening.
The show is generally a very well-done series and definitely worth watching.