Have you tried using a different monitor, see if the problem persists? Or equally using the same monitor with a different computer? All these can help locate where the problem is. It'd seem like a cable problem causing colour change, however, due to it persisting after five minutes, I'd suggest a graphics card fault.
Post edited at 3:39 pm on April 25, 2008 by marshmellowman
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and victorious in war shall be made glorious in peace.