TheyAreEverywhere

Does anyone know how to make replacers for in-game Banners, Posters & Paintings? I know some of them already exist but I kinda want to use my pictures. I already tried to create a mod. I downloaded the file of another mod, extracted it, changed the pictures, and converted the folder back to a ba2 file. I then dragged the file to Fallout 76 Quick Config and installed it. Everything worked fine but all the Paintings were just a purple colour. Does anyone have a guide? Or maybe even a program [Like in Starfield or Fallout 3] Thanks in advance