Whoops, that was rather silly of me. I forgot to actually encode the new imported image and the editor was simply saving the old picture rather than the newly imported picture. That's some bad testing skills on my part... I've commited the fix to GitHub, but I still need to pump out the binaries. Those will follow soon. Also red means that that texture has been modified but not saved yet. That actually also contained a bug. And yeah, the names stay the same. That is because those names are the "names" for that texture even though it looks like a path to a png file.