I have the exact same issue, happened in the exact same manner. Unfortunately the answer to this problem as far as people have told me is to replace the screen. Since in my case under the patch I can see clearly that colors are displayed well. And by this I mean the Green battery logo is still green I am thinking maybe we have burned the top glue and that is what is causing the weird colors. I am thinking about trying a top glass replacement ( not me obviously because I don’t have the right tools ) and see after as I don’t want to replace the screen because I will loose true tone and also refurbished original OLED is quite expensive. Please post here your resolution because I am interested in this topic