Why is the entire display suddenly displaying incorrect colors?
Monitors use a DAC (digital to analog) circuit to convert the digital information maintained in the random access memory of the video card into the analog signals used to control the monitor’s electron gun. If the entire screen suddenly starts displaying colors incorrectly, it can indicate a failure of the DAC circuit in the monitor. Try using the monitor on another computer to ascertain if the problem resides with the video card or the monitor.
