When you have a design with hundreds of layers, organized inside each other, and create or modify some element on the design without having previously selected the folder where to place it, you can find that layer in the studio panel because the color is highlighted. But that highlighting is very weak and sometimes difficult to find among hundreds of folders and subfolders.
You could also Extra highlight tabs of open files.
I've just deleted a photo that I wanted to save, and it's not the first time, because I had opened 8 photos of which I wanted to erase most of them and I got confused when I've started clicking on the X to erase them, especially because a natural order is not followed, photo showed does not match the order of the top menu, it should be the one from the left of the top tab menu or be more highlighted.
I work in both, Affinity Photo and Affinity Designer
Thanks for your great job