TV with Xbox 360 showing only black and white?

It's flatscreen Samsung LCD TV, if that helps, but I'm pretty sure it's a problem with the Xbox since the TV menu is in color. It was working fine yesterday, and for some reason the screen is black and white now. I tried replacing the AV cord and moving the wires to different spots, but it didn't help. The Xbox worked when hooked up to a different TV. Not sure if there's anything I can do to fix it short of sending it to Microsoft, and I'm trying to avoid that, any advice?