[bluGill]

The US. They are mostly green, but a lot of them have a blue tint for the colorblind. I suspect other countries as well, colorblindness is very common and this is a simple adaptation.

[bigstrat2003]

I wouldn't call "green with a slight blue tint" a blue light, personally. That's still a green light.

[bluGill]

As someone who has trouble seeing green, often I would call them blue. I don't expect my experience is normal.