All I have is 9V (track and motors) so all of my stuff will be 9V. I have no opposition with using RC track but my trains will not be able to run on it. As far as color, since this is winter, I was planning on covering most of my track with white plates/tiles, leaving only the rails exposed. Similar to my KidsFest layout where I embedded the track in the street.
Here is a picture of my “embedded” track – http://www.flickr.com/photos/41914153@N03/8190019240/.