Projection TV question

I just recieved a Sony 57" projection tv from a family friend. When you first turn it on the picture(color) is fine but, after a about 20 to 30 seconds it gets a blue hue to it. We've tried adjusting the settings but, no go. Anybody know anything about these? The only $ I have in it is gas going to get it so if it is a cheap fix I'll anty up. If it needs much it's gone. Let me know Mike.