Calibrate your monitor either by using the Operating System’s calibration feature or a hardware colorimeter to create a good color profile for your monitor.
Here is an article that explains how to calibrate your monitor: Resetting the Lightroom preferences to their factory fresh state can solve many abnormal and intermittent behavior issues.
If this does not work, or cannot be done, then your next option is to perform a clean install.
Hopefully you have a full and recent backup of your files at this point, because doing this will erase all files on your hard drive.
To do so, first set up a new user account with Administrator rights and test in this new account.