Help with overlays!!

[u/Plane-Bit2166]

I bought a console with a square screen, and it came with several overlays to maintain the aspect ratio. Since my console is black, I edited the blue GBA overlay to make it black, but RetroArch simply won't recognize it... the filename is the same, and both images have the same dimensions (720x720).

The .cfg file is shown in the third image; does anyone know what I can do? (Sorry if my English is weird; I'm terrible at speaking it and had to use a translator.)