I don't trust Oracle to not sue me whenever they feel like it. I refuse to work on any Java codebase as long as Oracle has anything to do with it.
https://openjdk.org/legal/openjdk-trademark-notice.html
Not worth the risk of stepping on their toes. There are plenty of other good programming languages to choose from.
If you bake a cake, it probably contains a dozen ingredients that have trademarked names. You aren't in any legal risk from doing so.