I just realized this as I test my forum out that there is no way to choose a default custom header and that the default one is the blue one and there is no way to change it either which is aggravating because my whole forum is dark red and gray and the blue default header just breaks the whole thing up. Its really icky looking too.

Edit: So, my suggestion is to be able to choose the default custom header if enabled.

Edit: Nevermind I found a way to do this but I guess my new suggestion is an easier way to setup the default header and for it to properly tile the background.