Can't set a custom wallpaper

[belaboy]

Been wanting to add a custom wallpaper for my SE/30 running System 7.5.5, but for some reason I can't get it to work. I tried using Backdrop, BackSplash, and Decor, but the images refuse to apply! Even did a fresh install and still no dice. Anyone have any idea what might be blocking it?

 

[techknight]

Its probably the image format itself. Back then software was picky on image formats. 

if its a PNG or a weird type of alpha enabled JPEG, forget it. Needs to be a GIF with compatibility and dithering or something along those lines.