How can I reset Deepin 15.5 to factory default settings?
 

I messed around with the special window settings in chrome, the opacity to be precise. And now the special window settings don't appear when I right click on the chrome window (it does appear on other applications). So how can I reset those settings? If fixing it isn't possible, can I revert all the settings back to their defaults? (I installed the resetter application but it says it doesn't support 15.5)

I'd try opening my filemanager - select show hidden, look for chrome dir. It maybe out in the open as a dot file or within .config dir, then delete it. this removes any setting and everything it has on your settings and such. then re-open chrome, where it will go back to default setting and create a new dir in your home for your setting on it.