Once the menu is accessed, you can select "Launch with verbose logging."
After you quit the game, the log will be saved to /dev/shm/runcommand.log.
This location is a temp filesystem that only exists in memory. You must access the file while the Pi is running, without shutting down or rebooting. (Specifically, you cannot pull the SD card and read the file off it from another computer.)
Unfortunately, this location is also not accessible via the network share. You should copy it to one that is.
Many thanks for the hint. I did know about that feature, but I couldn't find the exact path of the log-file! Your info will help me alot in the future. Thanks!!
You may have stumbled upon this bug. Can you try updating from source again and try loading a game to see if the palette works ?
That's it. FIXED. Many thanks!!!