A red icon is for a P25 Exclusive System and a blue is for a mixed-mode system (P25 and analog). If a system uses P25 ONLY, you have to program it as a P25 system. If it is a Motorola system that uses analog and P25, you have to program it as a Motorola system. Found this out the hard way when I programmed a mixed-mode system (P W County) as a P25 system and I never heard any traffic. Reprogrammed it as Motorola 800 and it worked fine.