Actually it is not Suspect. Most states have a provision for volunteer firefighters and such to have a certain color light In Illinois all they can have is blue with no siren. Others can have blue with siren. Some red and blue.

It is more common than you think.

I have two deckblasters in my back window and two hideaway strobes in my front turn signal lights. And a dashking in my front window behind the mirror. I will try and take video of it and post it.