Is it a conventional CRT TV rather than a new style Plasma LCD. If conventional, without getting too technical the light beams in a TV are controlled by elecrto magnets. During a power surge the voltage in the magnets can change messing up the colours, usually at the corners. Modern CRT TVs have a reset called a DeGauss that corrects this again when you turn on the TV, which is probably what happened once the power stabilised. Same effect happens if you put a Magnet ie unsheiled speaker, too close to a TV.
Last edited by Phil; 09/03/09 09:52 AM.