3D glasses and polarization, how it works?

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I was thinking about how does the 3D glasses(not the one with red and blue lens) work. My first idea is that the lenses are polaroids with orthogonal polarization. So I got a 3D glasses from a cinema and try to prove it.

I wear the glasses properly(with the arms on my ears) and then look at my LCD monitor. if I rotate my head to about 45 degree, the whole scene becomes bluest. If I rotate 45 degree to the opposite direction, the whole scene becomes yellowest. The same for both eyes.
I also get the same result when I look at a rainbow, which should be polarized.
I do the experiment with LCD monitor again, but I am not wearing the glasses properly this time. I look through the lenses in the reverse direction(with the arms pointing to the screen) and the result is different. For 45 degree anti-clockwise rotation, nearly no light can pass, and for 45 degree clockwise rotation, the brightest image can be seen. The same for both lenses again.

If my idea is right, here is my question:
1. If I wear the glasses properly, I expect the image will be dimmer and brighter as I rotate, but why is it isn't the case and resulting in the change of color?
2. Why isn't the result be the same when I look from different side of the lenses?
3. The images are the same when I look through the left lens and the right lens, that means they have the same polarization, so how could we perceive a 3D image?

 

[Andy Resnick]

There are several approaches to 3D movies/tv/etc. AFAIK, 'passive' glasses use circular polarization: the combination of a linear polarizer and quarter-wave plate. This is so you can tilt and swivel your head around and still maintain the 3D effect:

http://en.wikipedia.org/wiki/RealD_Cinema

In order for the projected scene to maintain polarization, a metallized scrim must be placed behind the movie screen.

'Active' glasses have lcd elements that alternate viewing through the left or right eye:

http://en.wikipedia.org/wiki/Liquid_crystal_shutter_glasses

I'm not sure what magic Nintendo invented to do this:
http://www.nintendo.com/3ds/hardware
http://en.wikipedia.org/wiki/Parallax_barrier

Your lcd display produces linearly polarized light- if you turn your glasses around ('backwards') the linear polarizer is in front and this explains your results. Wearing the glasses normally, the color shift occurs (AFAIK) due to the chromatic variation in retardance of the quarter-wave plate.