My boys used to get their hair cut at Harmony Barber Shop every trip, they got colored gel and pixie dust, which brought a lot of attention throughout the day. Hook accused my DS of being Peter Pans spy because his hair was green that year.
I had heard that colored gel was no longer available from the manufacturer, if that's true, it's sad because the colors were part of the reason we went.
My boys are 14 and 19 now, so we don't go to the barber shop anymore, but I highly recommend it to everyone.