What OS is installed in the laptop?
Try starting the laptop in safe mode to check what colour the screen is.
Search online for (insert OS) safe mode for how to do this, e.g. Win 7 safe mode or Win 8.1 safe mode or Win 10 safe mode.
If the colour is OK when in safe mode then you have a video driver problem. The screen may look different because only the basic drivers have been installed in safe mode. It is the colour that you’re interested in, not the screen resolution when doing this.
Restart the laptop in normal mode and go to Control panel > Device Manager > click on the arrowhead to the left of Display Adapters and then right click on the display adapter entry > Uninstall and follow the prompts.
Restart the laptop and Windows should "find" the display adapter and reinstall the drivers for it.