Unable to import highest quality texture (from wallpaper)

I'm trying to import some wallpaper textures from an existing file (this is from Natanec's blog). When I scroll through the warehouse two of the three swatches load with transparencies / little white dots. Brown panel on bottom loads perfectly, but the white and black swatches are having issues. Same problem with the glitched textures happened when I loaded through the Textures tab on the windows version as well. How can I obtain the highest quality texture the game loads ?