Here’s a Globe and Mail story describing the introduction of blue flashing lights on police vehicles in Ontario. Interestingly, it mentions that the blue lights are easier to see at night, and that the new lights are being introduced during a changeover to LED light bars, so there’s no additional cost for red and blue versus red only.
I have seen this in Ontario. The firefighting vehicles are equipped with the usual red lights, but the volunteers’ personal vehicles have the flashing green lights. The ones I’ve seen have been either put on the dashboard or have magnets so they can be put on the roof. When the call goes out, the volunteers respond and use the flashing green lights on their way to the firehouse.
Hey, Spoons, how’s it going? 
More years ago then I care to search and find out, I posted here asking why the UK and Europe all seem to use blue instead of red for emergency vehicles. Since humans are hard-wired to recognize red as danger (because of blood) using blue always seemed counter-intuitive to me. Just doesn’t have that sense of urgency to it.
Does this mean that, like the temp or oil pressure warning light on a European or British car’s instrument panel is blue also?
And please, no arguments about the ‘red/blood’ thing, Cecil already mentioned it in his column about traffic lights…