sisyphus,
Being seen (in the sense of staying clear of collisions) is also a concern of mine. Red will be sorta’ OK in daylight, but definitely not so at night. Silver will be an increment better than red (at night), but still not the best. Here’s a good read on the subject:
http://hera.ugr.es/doi/15019548.pdf
For me it is white on a black trid. Ever wonder why all the black & white circles on crash test vehicles (even the dummies heads)? Not targets, but points of reference that can be best seen by the cameras.
Go to the smartcar of America homepage (
http://www.smartcarofamerica.com/index.php ) where they have the animated smarts moving back-and-forth in the masthead. Which one strikes you as most immediately visible?