there is! go to settings>canvas and you can change the background color, there’s a list of them, you also can go to settings>capture to get a secondary capture window so the UI doesn’t appear on the capture!
Oh yeah, i know the issue, it’s OBS, their browser sources are slow af, if you try to use the link on a chrome/firefox browser window, you’ll see it works great, it’s just OBS that it’s slow :(