In 2008, shoe designer Christian Louboutin was granted a U.S. trade-mark registration for “a lacquered red sole on footwear” as applied to “women’s high fashion designer footwear” (U.S. Reg. No. 3,361,597). Louboutin’s red-soled shoes have become famous worldwide, as well as highly sought after by celebrities and fashionistas alike. However, Louboutin’s U.S. trade-mark registration has recently been challenged by the fashion house, Yves Saint Laurent, which also features red-soled shoes in its fashion collections. Saint Laurent claims that the use of colour in the fashion industry is intended to please the eye rather than to identify a commercial source. The U.S. District Court for New York agreed with Yves Saint Laurent and found that the colour red as used by Louboutin is aesthetically functional and therefore not entitled to trade-mark protection. Judge Victor Marrero found that granting trade-mark protection to a colour in the fashion industry unfairly impacted competition, “cramping what other designers could do while allowing Louboutin to paint with a full palette.” Surprisingly, the court seems to have ignored the significant customer recognition and acquired distinctiveness of Louboutin’s red soles. The District Court’s decision suggests that any use of colour in the fashion industry constitutes an aesthetically functional use. Louboutin has appealed to the U.S. Court of Appeals (Second Circuit), and we will continue to monitor this case as it will have significant implications for fashion designers. See Christian Louboutin S.A. v. Yves Saint Laurent America Holding, Inc. 2011 WL 3505350 (S.D.N.Y. Aug. 10, 2011).