Right click on desk top
Select personalize
Select High Contrast Settings
Turn on high contrast using the sliding button
Select background and choose a colour that is tolerable for the user
In Windows 11, high contrast mode is handled through contrast themes.
1) Right click on the start menu button
2) Select Settings
3) Click on Accessibility
From here you can either select Aquatic, Desert, Dusk or Night Sky as your theme.
Select whichever theme is clearest for you to see with.