Why does our computer screen turn yellow sometimes

It's most likely that you have a loose or bad cable. Specifically, the pins handling blue are probably bad or loose; either 3 or 8. Take a look at the image below and it will help to see why this iis happening.


If your cable is built in to the display then it could be diffcult to fix but if your cable has connectors on both ends it is pretty simple to just get another one and try it. Be sure to inspect the pins on the connectors at both ends and carefully straighten any that are out of place.

There's also an outside chance that the same issue is occuring either on the video card itself or internal to the display.