I created a custom theme using a picture from online through Firefox Colors. Whenever I log out of Firefox browser, I have to go to Firefox colors in order for me to get that custom theme to show by going under my saved themes. When I try to export, it just makes me open it in a picture program on my computer. I can't keep this sucker enabled as it seems Firefox doesn't want to save and apply it. I have gone all over the settings about light, dark, and other themes. Nothing should be causing this. Uninstalling the Firefox Colors, reinstalling it, and redoing the ENTIRE theme all over again has only resulted in it not being saved and me going through Firefox Colors every time just to get the theme I want.