Changing the comments bracket color?

I just recently got Scrivener, and I’ve been customizing the preferences.

I have some documents in which I’m creating a large number of comments. I go back and forth between regular scrivening mode and full screen mode, and I’d like the comments in the text to be as least intrusive as possible.

I’ve determined that for the comments selection I can set the alpha channel to zero to make it invisible. However there is still a red selection bracket around the text. Does anyone know if there is a way to change that red bracket to a different color? Thanks!