Any good auto paint supply shop will carry a spectrometer. Its a gizmo which they press up against the original painted surface, then the computer tells them what quantities to mix the paint in to achieve the exact same shade. I've had spray cans mixed for me this way, but they can mix touch up pens or even larger quantities.
Maybe you could either take the TV with you, or offer them a couple of drinks to make a house call.
If I remember correctly, the BMW silver is Arctic silver 309.
Cheers,
Ben