Many people associate brands with particular colors – if you think of Tiffany & Co., you think of its famous robins-egg blue boxes and branding; if you think of Barbie, you can see the bright pink that came with so many childhood toys. Not many people realize, however, that brands can trademark those colors and prevent others from using them.

The first company to trademark a color was Owens-Corning. Owens-Corning created a new type of fiberglass insulation and dyed it pink to distinguish it from competitors. Owens-Corning leaned into the pink branding, including licensing the cartoon character Pink Panther to promote the products. In 1987, it was awarded the first ever trademark of a color. It now owns the signature pink color used in its proprietary insulation.

Other companies followed suit. Tiffany & Co. holds the trademark for its robins-egg blue, UPS trademarked the “Pullman Brown” used on its trucks and uniforms, and T-Mobile’s parent company trademarked its famous magenta. 3M even trademarked the famous, albeit nondescript, color of its standard post-it notes.

However, not everyone can trademark a color. There are two key hurdles to obtaining a color trademark. First, the color has to distinguish the business’s goods and identify that business as the source of the goods. If the color is commonly used by all business in the space, the trademark may be rejected. For example, Cheerios was denied a trademark largely on the grounds that many kinds of breakfast cereal use the same or similar color yellow. The court found that it had not acquired enough “distinctiveness” in the eyes of consumers.

Second, the color cannot serve a functional purpose. For example, Pepto-Bismol was denied a trademark on the color pink because of the color’s “therapeutic value” in treating upset stomachs. The court reasoned that Pepto-Bismol’s competitors might want to use that color in order to compete effectively in the market.

New brands should be wary of using colors that are already trademarked or heavily identified with a particular brand. Established brands are extremely possessive over their colors and will not hesitate to file lawsuits against infringing brands. Just recently, Mattel filed a lawsuit against a potato chip manufacturer for selling “Barbie-Que Honey Truffle Potato Chips,” which used Mattel’s signature pink color on the packaging. Companies should be careful to distinguish their branding and colors before spending time and money on an infringing design.