Hi there, @sschn500 ...
Are you referring to the text box on the bottom right side of the SpeedGrader where you, as the instructor, can type in comments/feedback for your students? If so, this area does have a bit of a RCE (Rich Content Editor) built in. I'm not sure if your screen has this or not (I believe it should), but there is a three vertical dot icon (sometimes known as a kebab) that you can click on to show additional tools. If you click on this icon (next to the "Paragraph" option), you'd see things like bold, italics, underline, color options, etc. Is this what you're looking for?

I hope this will help in some way. Sing out if you have other questions about this. Thanks!