Christian Louboutin launched a trademark infringement case against Yves Saint Laurent (YSL) in 2011, saying that YSL’s high-heeled shoes with red soles were too similar to his own red-soled shoes, confusing buyers and hurting his business. YSL said that Louboutin’s red-sole trademark was unenforceable because colour cannot be utilised as a trademark and red is a common design element in the fashion business. The US Court of Appeals for the Second Circuit determined in September 2012 that Louboutin possessed a valid trademark for his red soles, except when the red sole was used on an all-red shoe. YSL’s monochromatic red shoes were found not to infringe on Louboutin’s trademark, allowing both companies to win. The case highlighted the significance of trademark protection in the fashion industry, particularly concerning the legality of color as a trademark.