Two stage amber was the name the military gave it when they used it.
Orange film or plastic in the windows....instructor sees everything bright orange outside..sort of like ski goggles.
Student wears blue goggles and everything inside the airplane is blue tinted but everything outside is black.
This is a far better way to teach instrument flying because the student sees everything inside the airplane normally instead of like a tunnel when wearing a hood.
Why did they quit using this logical excellent means of simulating flight in cloud?