Discussions about the Notes and Journal tool on LDS.org. This includes the Study Toolbar as well as the scriptures and other content on LDS.org that is integrated with Notes and Journal.
You should be able to select the color - there are 10 to choose from. After you highlight the selection you want to annotate, wait for a couple of seconds, especially if you have just signed in to study mode. A box should appear with the colour options and the words Add Note/Tag, and you also have the option of choosing 10 different colored underlines instead of highlights.