Please note that if you have an HDR monitor, then it is best to temporarily disable HDR mode for ExPra experiments. On Mac, go to "Settings->Display" and uncheck "High Dynamic Range". On Windows, search for "HDR" in Settings and turn off HDR mode and HDR streaming. If your computer does not show these settings, then you do not have an HDR monitor and can ignore this advice.
After the experiment is finished, you can reenable HDR mode.