Why green windows on commuter train?

Hello
I've never seen these colored (green) windows before, that can be found on the Metra bilevel cars and on the NJ Transit Multi-Level cars.
What is the reason for these green windows?

Pics:

• Metra cab cars—night shot at Hill Yard
  Metra at Aurora IL
  More Metra
  Metra #6475
  
  YouTube Video of NJT multi-levels

Ok, I can't say to 100% that the NJ Transit windows are green…

Cheers!

Tinted windows keep out a significant amount of heat from direct sunlight in the summer, resulting in less energy diverted from propulsion to air conditioning.

I remember the Reading's old RDC's had green windows back in the days when I would ride the Newtown branch. Their MU's did not.

The windows are not green. What you are actually seeing is the fluorescent lighting. Fluorescent lighting has a green tint when photographed. The light is actually that color, but our brains 'convert' it to white. Cameras do not have this 'color conversion', so the true color with the green tint is captured.

When on a Metra train looking out the window, the whole world outside is green even when the lights are off.

it also probably makes it alot better on our eyes during the sun.

I definitely think Toronto's GO trains are tented green.

My '07 Hyundai Sonata has green glass. They market it as a solar glass called 'Herculite' in it that supposedly keeps it cooler in the summer while parked and of course also when in use. It doesn't look that green but if you see the sun's light through the windows cast unto the ground it is clearly green. As I bought the car late last fall and it hasn't been summer hot yet, I can't attest to its effectiveness.