There might be times when the additional monitors you connect don’t display the correct colors. It may appear faded and it does not match the normal color tone. In this case one should normally check whether the cables are connected properly or not. If the cables are loosely connected there is always a chance of the display settings falling apart.
If you find the problem still existing, you could check the Windows Color Calibration Wizard. In a series of steps it will guide you to get the perfect color setting for your computer. Here is the link http://windows.microsoft.com/en-us/windows7/calibrate-your-display