Free tv repair advice

Hello,
My sony big screen televison(not flat screen, just the tradition big screen tv with rear projection tubes) has started to give a problem with the picture. The problem is that the picture is fine color wise for 10 minutes, and then proglessively loose its other hues, and becomes progressivley more and more blue/green. what can i do to fix it?

Sounds like your loosing on of the picture tubes. Probably getting to the age where the crt's are getting week. You might try gaining acces to the g2 settings are try adjusting them ever so slightly when the set is warm and see if you can adjust it.