Pons_Aelius, 1 year ago (edited 1 year ago)

According to wikkipedia:

Blue and green stop signs are sometimes used on private property in Hawaii.

But they only have a picture of a blue one and not a green.

https://en.wikipedia.org/wiki/File:Blue_stop_sign_-_hawaii_-_oct_2015.jpg

So my guess is photoshop.