And let me tell you something it's not easy playing how to fix this over an audio call on a cell phone, especially when your trying to have a quick bite to eat during a break.
During the course of this fix the poor man accidentally saw the "color" on the side bar of windows 10 settings personalization settings and turned on dark mode, and then proceeded to say "things got really dark" To which I just had to pause and b like uhhhhh ??? Before it clicked that he probably clicked on dark mode.
Additionally what the tech should've done was just have him click on and of the displayed photos in the "picture" mode of the background tab, as that forced whatever mythical magical cache AD photo + windows background image to properly update and come back to its correct color