ThemeSwitcher-for-SumatraPDF

1. Make 2 SumatraPDF-settings files with values you like adjust contrast/brightness by modifying Properties

SumatraPDF-settings_DARK.txt

FixedPageUI [ TextColor = #ffffff BackgroundColor = #212121 ]

SumatraPDF-settings_LIGHT.txt

FixedPageUI [ TextColor = #000000 BackgroundColor = #FFFFFF ]

2. just run the app, it will switch between these 2 settings