My car does not have the TV option but I will check the connections on the back of the monitor. Is there another unit somewhere in the car that produces the picture from the navigation computer or does the picture come directly from the computer to the monitor?
I'm hoping you're onto something here as it seems that the monitor may not be getting the blue input. The small box in the top left corner that shows direction of travel has a pinkish background and I have noticed from screen shots on the internet that it should be a blue background. And obviously my beige sky is missing some blue....