Watercolor paper textures are the new trend in blogs. In fact, it was there earlier and has shown a comeback recently. The reason why it is used is that
it is beautiful and soft and very feminine.
People use these WordPress design templates as they are very simple to use. They can be added in splotches for the entire background as well as throughout the design. If the blogger does not want to use it throughout the entire website, it can be used very creatively as addition to the headers and so it appears only for the topic headings.
It can be used artistically as icons for social media as well. Some bloggers use the watercolor paper texture for header elements. They could be used to make the logo stand out. There are also various shapes of these that can be used to highlight certain icons.
When designing a logo, these watercolor blots as well as brushes can be used to create the entire logo. It could be used to add effect to the text which has been added either on the logo or on the page itself. This could be used in sidebars, header, and footer areas as well as in opt-ins too.