Facebook has sued a German social networking site, saying the site stole its look and feel by creating a clone site and merely replacing a blue background with a red one, according to a report in the Financial Times.

The site, studiVZ, is available in French, Italian, Polish, and German. Its membership comes mainly from Germany, Austria, and Switzerland. In 2006, a publishing company, Hotzbrink Group, bought the site for more than $110 million.

The company has denied Facebook's intellectual property claims, which were filed in federal court in California. It said the American social networking site is suing because it has failed to gain popularity in Germany. It has requested a declaratory judgment in a Stuttgart court.

Facebook called the site a "counterfeit product" in the complaint and said its "uncontrolled quality standards for service, features, and privacy negatively impact the genuine article."

Facebook is seeking compensatory damages from StudiVZ but has not specified an amount. It filed suit right before unveiling a redesign.

A news article on Mashables last year listed StudiVZ as one of the 10 most profitable "copycat" Facebook sites. Several German sites were listed, as well as similar sites in China, Russia, India, Turkey, and Australia. The Australian site is called StudentFace and it features feeds that informs users when their friends have updated profiles or added friends.

Several of the similar sites share Facebook's blue background. It's unclear whether the social networking site will go after more companies, but it seems likely.

Facebook founders were accused by fellow students of stealing the idea for the site. The company admitted no wrongdoing and settled the case out of court.