Bright green "tail light" in a caravan

[Jim]

In the early morning hours on I-95 in Georgia last night/today, we passed a caravan of a couple dozen trucks, many marked as New Jersey Urban Search and Rescue.  My guess is that they were headed to help out with recovery in the condo collapse, but I really don't know.  My question is about the bright green lights they all had on the top of the driver's side of each vehicle.  They also had bright yellow flashing lights in a more usual place like you'd see on construction vehicles.  I don't remember seeing bright green lights on vehicles like that.  Was this supposed to convey some information to other drivers, or just to each other within the caravan?

[hobsini2]

Green, along with yellow and purple, means it is an emergency vehicle but it is not required to give way to but rather "requesting" to have the right of way.  That is a common color used in vehicles associated with disaster relief and storm spotters/chasers.

[GaryV]

I've been seeing more and more highway work trucks with both green and amber flashing lights.