Windows has a magnifier application which also has a colour invert option to make things a little easier to see .
.....to switch it on and right click the taskbar icon and hit 'X' to switch it off.
With the application running, click the taskbar icon...
...to bring up the options window...if you see a magnifying glass, click that...
...on the options dialogue box, click Views and select Lens...
...then click the gear wheel to bring up the options...
...click the colour inversion check box to apply that feature.