Video Card for MacBook Pro Question

Hi,

I recently experienced my computers display having a blue tint, which I took my laptop to Apple and they said it was the actual diplay so after replacing my screen the issue was not resolve so she said it was mostly my logic board. I had asked if it could be my video card and she said that it looked fine, that being they had to order my logic board. I don't live near the Apple store and am a college student so I took the laptop back with me so I could do school things. Well tonight I was on facebook and the display changed from a blue tint to normal to a slightly less bluer tint and eventually the display went back to normal. Confusing I know. I was wondering, could the real problem be my video card and she just not have check it as well as she thought or what? I notice when I change taps that the video messes up for a nanosecond an then is normal like it loads the image and you can see it, if that makes any sense, but it works perfect. I also noticed the night before the computer's display had this blue tint it was running a lot hotter than normal. I asked if this could be the problem and was told mostly not, but I would think that would do something.

Thanks.