Hmm... well... good points (as usual), Al. I would have assumed that properly protected blue or red cold cathode tubes would be okay (assuming green is the only target), but you've got a point about the transformer pumping the voltage up. Although I would suggest that some reasonable level of LED lighting in a colour (or spectrum range) different from any vision targets should be okay, I would suggest teams make a point of clearing up any potential misunderstandings in the Q&A forum next year before decorating a robot with shiny flashy things.
I would suggest to anyone terribly disappointed by the concept of having cold cathode tubes potentially nixed at tech inspection that they consider lightsticks, such as cyalume
http://www.cyalume.com/ They are plastic, chemoluminescent tubes... crack them and shake them at the start of the day and they should last for several hours of cool glowing robotness on the field, and in the pits... without draining batteries, or exposing anyone to high voltages, or the potential for cracked glass on the playing carpet.
Jason