I feel that it is important to maintain a professional image to city officials. In many cases, they don't know you or the company that you are representing and if there is any doubt throughout the process, the Pro will get the benefit of it.
I have had sign companies send me a box of painted wood chips when I requested a color board. The samples were not labeled or mounted and I will NOT attempt to submit a box of random painted wood blocks and try to pass it off as a Color / Material board. Try fitting that into a file folder. The one thing that you definately do not want to do is make the Planner think you are sloppy and inconsiderate, not that they would accept it anyway.
I prefer to make Color / Material boards out of mat board (8.5" X 11") so that they will easily fit into the file. I do the layout in Corel Draw, listing all of the color call outs and identifying where the color can be found on the sign. I have even printed out the sign detail and connected the samples with arrows - very effective. I print the sign company's logo at the bottom, along with the sit address. I then use spray adhesive to attach the printed out sheet to the mat board. Hot glue usually works pretty good to attach the samples or plex, trim cap, vinyl, etc.