In most Web projects, only issues of copyright need to be dealt with, not those of industrial property rights, such as patents, designs, and trademarks. However, in some projects, industrial property rights may be relevant. For example, while trying to develop an effective process, a unique algorithm might be computed that is worth patenting. Some dating websites, for example, have their matching algorithm patented. This happened before with data compression algorithms for various media types. If you feel that your site will do something unique and groundbreaking, the next step should be to take legal advice, as patent applications are often complex. On the other hand, given that patent eventually expires and an idea becomes free for people to exploit as they see fit, if your idea is likely to be relevant and profitable for a long time (as, for example, Google’s search algorithm is), it may be better to simply make the details trade secret and not patent the idea.
Where a project includes producing a trademark, caution would have been taken during design and production to ensure that it is not too similar to any pre-existing one, bearing in mind that even too much similarity in color scheme can constitute trademark infringement. Of course, trademarks are usually registered by the clients, not the Web designer.
Source: Sklar David (2016), HTML: A Gentle Introduction to the Web’s Most Popular Language, O’Reilly Media; 1st edition.