Square borders can be adjusted. Circle borders don't.
I'll give some summary:
@lgp - Turns on those colored squares
After turning this on, you can use these commands:
@circle - Turns on/off circle border
@square on/off - Turns on/off square border
@square 1-10 - Changes @square size
@aoes - Turns on/off area-of-effect lgp squares such as Storm Gust/Lord of Vermillion or Meteor Storm. They are shown as colored triangles if enabled.