Metro Cleveland, police use red and blue (and white strobes).
They may have changed since I left, but in Southeast Michigan, when I lived there, a lot of police departments used only blue from the mid-60s on, while a few departments used red and blue (with some white). State police used only a single red gumball machine* while municipalities used a pair of gumball machines, later replaced by light bars. For a number of years, Detroit police used a single blue gumball light while the Tactical Moblile Units (S.W.A.T. lite) (that later had their name changed from TMU to something else) used a pair of gumball machines–one red, one blue. I’m sure that Detroit police are using lightbars, now, but I haven’t been stopped when traveling home to visit family, so I do not recall whether they are still all blue.
When did the volunteer firefighters switch to blue in the Northeast? I don’t recall seeing that in any of my trips out that way–although it has been more than ten years since I’ve had the chance to visit.
- From the resemblance of the light housing to a coin-operated gumball dispenser near the front of stores.