Under some circumstances, trademark protection can extend beyond words, symbols, and phrases to include other aspects of a product, such as its color or its packaging. For example, the pink color of
Owens-Corning fiberglass insulation or the unique shape of a
Coca-Cola bottle might serve as identifying features. Such features fall generally under the term "trade dress," and may be protected if consumers associate that feature with a particular manufacturer rather than the product in general.
However, such features will not be protected if they confer any sort of functional or competitive advantage. So, for example, a manufacturer cannot lock up the use of a particular unique bottle shape if that shape confers some sort of functional advantage (e.g. is easier to stack or easier to grip). Qualitex Co. v. Jacobson Products Co., Inc., 115 S. Ct. 1300 (1995).