Christian Louboutin, producer of red-soled footwear usually sold for around £600 a piece, went through a period of worry over the distinct red soles, made famous partly by the popular series “Sex and the City”. The designer convinced the US Appeals Court in Manhattan to grant protection to the shoes with red lacquered soles and contrasting top – a combination worth millions and recognised by everyone in the industry. The action was fought against Yves Saint Laurent (YSL), part of the Gucci Group.

The case brought by the designer brand fits into the wider discussion about the use of colour as a trademark. The outcome of the case could have had a potential large-scale influence on some major worldwide brands. Public recognition of unique use of colour is often viewed as a selling point appealing to customers. Interest ranged from exclusive jewellers Tiffany, the owner of the trademark on the distinctive blue coloured boxes, to brands recognised mainly within certain trades – for example Owners-Corning, using pink to identify its insulation materials.

The dispute between Louboutin and YSL, regarding the sale of colour-soled shoes by YSL, started in January 2011. Louboutin objected to the all-red shoes being sold by its competitor, claiming they were too similar to his unique red sole design. After a brief period of unsuccessful negotiations, Louboutin decided to take things a step further and sued YSL. The accusations included, inter alia, trademark infringement and unfair competition. In response, YSL retaliated that the red sole was not a “distinctive” feature but a mere ornament and that it was a “functional” part of a shoe.

At first instance, the District Court refused Louboutin’s claims. It explained that in the name of creative freedom of fashion no one could stop other designers from using red soles in their products. On appeal, the Court decided that although the use of a red sole could not be prohibited in all situations, the so-called Red Sole Mark (red sole contrasting with the upper part of the shoe) had acquired a particular meaning, recognisable as the Louboutin brand. In this limited context, the contrasting combination - often worn by Hollywood stars - had a unique position in the public psyche, and could be protected as belonging solely to Louboutin.

In the UK, following the provisions of the Trade Mark Act 1994, it is possible for a colour to be regarded as a trademark. The most famous examples include BP green, Heinz turquoise cans and Cadbury’s purple wrappers. Although the use of the particular colour is not forbidden in general terms, it is not allowed within the specific field where it would cause confusion.