Using multiple colors for comments

I am grading student papers using Pages and I would like to be able to use more than one color when inserting comments. In particular, if I am commenting on two different sentences in the same paragraph, I want to be able to insert one comment using, say, the yellow highlight; and then insert the second comment with using, say, the green highlight. As far as I can tell Pages only allows the use of a single color for every comment and I don't want to use the text background color option to accomplish this. Is there a way to use multiple colors for comments?