Changing the contrast of your laptop screen affects how sharp different colors look against each other. Most operating systems have built in calibration tools that make your screen look as sharp as possible, but you can also manually edit contrast settings. Not all laptops have the ability to adjust contrast.
Right click your computer's desktop. Click "Properties".
Click on the "Display" tab.
Adjust contrast settings as desired. If your computer has this option available, there should be contrast and brightness settings that you are able to tweak (almost all laptops allow you to adjust brightness, but many do not have contrast options).