depends on which vehicles you are referreing to
the apparatus have red and white light bars and on the back there are red and amber rotators and arrow sitcks on the back the chief is considering adding green lights on the pumpers for when the trucks engage the pumps.
Most People on my dept. use amber, red, and white. We can not use blue. I have a red/white strobe on my dash and red and white gril light four each. Plus wig wags. On the trucks mostly red and amber. By the way the eight gril lights cost less than 100 $.
We have red and white rotators on all but the new engine and red rotators on the backs. The new engine has the LED bar and 2 rotating amber lights in back. And the grass rig has a strobe bar on it. But we run blue lights on pov's. Indiana won't let us have red. My old department runs red and blue's. Farmlandfire.com