I was having the same problem with my Haier TV. All of a sudden, it was in black and white after two years. I switched the input from Component to Composite, and it fixed it.
Mine is doing the same thing however i do not have a composite option so what do i do now
It may be refereed to as Video or something similar instead of composite. I had this problem on a Sanyo tv. Options did not have a "composite" finally figured it the menu was calling it "Video" might. be something else maybe AV.