Trade dress is a trademark type of IP covering the artistic context in which products or services, including digital services (websites), are presented to customers.
As legally defined in the US, trade dress is a trademark type of IP that covers the designation of origin (who made it) connected with goods or services used in commerce. It is focused on the overall artistic context (e.g. artistic impression as a whole). It can cover distinctive containers (packaging) for goods. It can also cover store or restaurant decor, website designs, and other miscellaneous “look and design” issues. The designation can be “any word, term, name, symbol, or device”. These latter two terms are pretty expansive and can include colors, shapes, and sounds.
Like all trademarks, trade dress can’t be functional, and instead only covers distinctive artistic elements. This is due to social policy considerations. Trademarks can potentially last forever. However, in earlier centuries, it was found that locking up “function” forever causes monopolies that can hurt the economy. Thus functional IP falls under patent law instead. Patents have far stricter examination criteria and only a 20-year lifetime.
The US legal system is still working to define the extent to which websites and other digital items fall under trade dress law. Courts may rule differently depending on the jurisdiction. The Federal 9th circuit, for example, determined in 2016 that the visual layout of digital reports can be covered, so long as the visual layout is not functional. This is present law in California and other western states.
Thus, for example, it is not a good idea to try to copy the distinctive layout of the Facebook website, at least in the social network space. You may think you are avoiding copyright infringement by using different text and images. You may think you are avoiding patent infringement by using different technical methods. But copy the trade dress, and you may still end up in trouble. Indeed, Facebook has a history of litigation in this area! The same advice applies with respect to other distinctive websites as well.
Like all trademarks, trade dress IP rights may also exist under state law and common law. Thus, the absence of Federal trademark registration is not an automatic “all clear” signal. Hidden problems may still exist.
As a rule of thumb, try to avoid copying the look and feel of a competitor’s website, or other digital output, too closely. If your competitor’s website has some distinctive visual or sound elements, consider making a different choice.
On the other hand, perhaps you have achieved a unique look, feel, or design for your website, service, or product packaging. One that you think customers will like and start to associate with you. If so, consider filing a trade dress trademark application for your particular class of goods or services.