The setting of your screen should allow you to identify each shade of color.
The basic table proposed here is usable for a quick adjustment by manipulating the contrast and brightness (buttons on the monitor).
The real solution is probably a hardware probe, and again not just any ... So expensive!
I suggest you also check the color temperature used by your monitor and select a temperature of 6500 ° K.
Every monitor has a menu button to access this kind of settings.