Different colour for frames and background of other frames?

I might be missing something, but I can’t see how to get my frame colours one colour, without that affecting the background colour of other frames. Specifically, I want blue for the colour of my bracket frame, but if I set this in the Advanced wizard, then it also makes the background of my rectangular frames blue as well. I don’t want this! Is there a way of separating out these two things? (If not, there should be!)