I have an open source software project under the 3-Clause BSD license, which includes a logo in its README. Recently, working on another project, I have found that the license text does not explicitly include the license under which the logo is covered. In this case, would the logo be covered under the BSD-3 license? Do I have to explicitly declare the logo license? Do I declare it in another file or in the same LICENSE? Modifying the license, if I need to, would that be a bad practice? Are there versions of the most popular open source licenses that include a mention of the project's graphic assets? Clarify that I do not want to create a trademark for the logo because I do not care whether it is used as it is, I want it to be under the same license or a compatible one.
Sorry for the barrage of questions, but I have a lot of doubts at this point about the use of graphic assets in open source licenses.