It could be the screen is inferior. It could be the graphics card is inferior. It could be the settings. etc

In Display (in control panel) there may be some options to change gamma, contrast etc etc, but this is often tied into proprietory software for the graphics card. Poke around in Settings/advance to see what you have available.

Often the computer will come with software for the video card where you can make adjustments.

Pro's will use colour correction software (with an external device to take readings from the screen) to make sure what you see on screen is printed (on calibrated printers) in the same colour.

The expert in this area is Boatone