French fashion designer Christian Louboutin is known worldwide for shoes with an eye-catching, red lacquer sole. When a well-heeled celebrity or socialite reveals that quick flash of red from the bottom of her sexy stilettos, it’s powerful publicity for the venerated fashion house. That’s why the couturier asked the European Court of Justice to stop Dutch chain Van Haren from selling shoes with a similar red sole, arguing that he had trademark protection registered in Belgium, the Netherlands and Luxembourg for that particular shade of red. But the court in February disagreed, saying “a trademark combining color and shape may be refused or declared invalid on the grounds set out under EU trademark law.” In other words, the color alone was not enough to protect Louboutin from knock-offs. Although the case is not over, it raises some interesting questions about the limits of trademark law and how far companies should fight to protect their brands.…