I would avoid choosing solid-color polos in any of the FIRST
"family of programs" colors, the dark green of the safety advisors, the dark blue of the FTAs, the light blue of the Volunteer Coordinators, etc. If you must choose one of these colors, please make your logo nice and big.
EDIT:
Collar or
sleeve details on team polos are also a really great way to distinguish yourselves from the pack.