I'm sorry so many people are having this same problem and being charged $600.
I took mine to my nearest Microsoft store and when the tech saw I had the yellow tint problem she immediately went and got a replacement out almost before I finished telling her what was wrong. She explained that the problem was caused by the swelling battery, and when she laid the screen unit down on the table I was shocked to see it was bowed and warped. She told me I shouldn't take it home again to do an additional backup because it could explode. She transferred my data and sent me home with a refurbished replacement machine.
A few days later I received a box designed to send back computer, treating it like hazardous material. They must have gotten their wires crossed, because they had already taken away and replaced the faulty one.
Apparently some stores are demanding payment for out-of-warranty replacements and some are not. Perhaps if people tell them that others are getting free replacements....?