[Rickertsen2]

Last year FIRST allowed our green underglow, but we programmed it to turn off during autonomous. This year cameras a used throughout the whole game. I would think any other color should be a problem. You could even have a red a blue set to match your alliance color. That would be alot more obvious than the flags.

In fact, i think it might even be a good requirement for or strong recomendation for next year. During the heat of a match, there is nothing worse than trying to figure out who the enemy alliance is.

the rotating lights - good
LEDS - pretty poor
Flags - much better than LEDs but not as good as the rotating lights
Neons - awesome

---edit----
On second thought an underglow requirement would create too many overrestrivtive rules about how high the underneath of your robot would have to be, neon placement etc. I still think they should be a "recommendation" as the team color LEDs were this year.